Forest Soil Disturbance 

Monitoring Protocol

Volume II: Supplementary 

Methods, Statistics, and 

Data Collection

By Deborah S. Page-Dumroese, Ann M. Abbott, and 

Thomas M. Rice

Schematics from Napper et al. (N.d.)

United States 

Department of 

Agriculture

Forest Service

Gen. Tech. Report 

WO-82b

September 2009
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Volume II: Supplementary Methods, Statistics, and Data Collection iii

Contents 

Acknowledgments...............................................................................................................v

General Summary ..............................................................................................................vi

Introduction.........................................................................................................................1

Electronic Data Forms .................................................................................................1

Historical Context for Monitoring Forest Soils...........................................................2

Soil Disturbance...........................................................................................................3

Why Use Visual Classes? ............................................................................................4

Current Forest Soil Needs............................................................................................7

Key Concepts...............................................................................................................7

Relationship to Other Federal Inventory and Monitoring Programs..................................9

Programs in Other Federal Agencies...........................................................................9

Changes to the Current Protocol (Change Management) .................................................10

Determining the Type of Transect To Use .......................................................................11

Stratifying an Activity Area..............................................................................................12

If the Unit Is Large.....................................................................................................12

The Number of Activity Areas To Monitor...............................................................13

Unique Monitoring Strategies...........................................................................................14

Wildfire ......................................................................................................................14

Prescribed Fire or Burn Piles.....................................................................................14

Unburned Slash Piles.................................................................................................16

Landings, Temporary Roads, and System Roads ......................................................16

Root Ball or Bole of “Tip-Up”...................................................................................16

Spreadsheet Forms............................................................................................................17

Paper Field Form........................................................................................................17

Portable Data Recorder and Electronic Field Form...................................................18

Field Data Collection—Standards and Methods........................................................19

Filling in the Worksheets..................................................................................................20

Data To Collect in the Office .....................................................................................20

Selecting Indicators....................................................................................................20

Monitoring Objectives...............................................................................................21

Step-by-Step Field Survey Method............................................................................21

Baseline (Preactivity) Assessment ......................................................................22

Postactivity Assessment ......................................................................................24

Interpreting the Results..............................................................................................25
iv Forest Soil Disturbance Monitoring Protocol

Definitions of Attributes and Indicators............................................................................26

Site Attributes ............................................................................................................26

Soil Texture..........................................................................................................26

Veget Soil[Vol2].pdf ation...................................................................................27

Soil Structure.......................................................................................................27

Activity Area History ..........................................................................................27

Soil Indicators............................................................................................................28

Machine Traffic Disturbances.............................................................................28

Displacement.......................................................................................................31

Point Attributes...................................................................................................32

Erosion ................................................................................................................33

Prescribed Fire and Pile Burning ........................................................................33

Assigning a Disturbance Class..........................................................................................34

Quality Assurance and Quality Control............................................................................35

Glossary ............................................................................................................................36

Literature Cited .................................................................................................................38

Appendix A. Options for Monitoring Point Layout..........................................................43

Appendix B. Statistical Background of the Forest Soil Disturbance Monitoring 

Protocol......................................................................................................................45

Appendix C. Examples of Worksheets Contained in the Forest Soil Disturbance 

Monitoring Protocol Spreadsheet...............................................................................49

Appendix C-1. Example Worksheet for Collecting Soil Disturbance Monitoring 

Data (SoLo Info) .................................................................................................49

Appendix C-2. Example Worksheet for Collecting Soil Disturbance Monitoring 

Results (Variable Selection)................................................................................51

Appendix C-3. Example Worksheet for Collecting Soil Disturbance Monitoring 

Results (Data Entry)............................................................................................52

Appendix C-4. Example Worksheet for Collecting Soil Disturbance Monitoring 

Results (Results)..................................................................................................54

Appendix D. Paper Field Form and Tables for Determining Sample Size.......................55

Appendix D-1. Example of Paper Field Form...........................................................55

Appendix D-2. Determining Sample Size With a Margin of 

Error at ±5 Percent ..............................................................................................57

Appendix D-3. Determining Sample Size With a Margin of 

Error at ±10 Percent ............................................................................................58

Appendix E. Example of a Form Used To Document Past Soil

Disturbance in an Activity Area.................................................................................59

Appendix F. Technical Specifications of Portable Data Recorders..................................60

Appendix G. Core Site Descriptors for Each Activity Area.............................................63
Volume II: Supplementary Methods, Statistics, and Data Collection v

Acknowledgments

The monitoring approach and methods in volume I and volume II are the result of extensive collaboration between the Forest Service, U.S. Department of Agriculture National 

Forest System and Research and Development. The Forest Service Rocky Mountain 

Research Station in cooperation with the Northern Region led the effort. Although the 

development of this protocol has been guided by suggestions from a large number of 

regional soil program leaders, forest soil scientists, research soil scientists, university 

professors, and British Columbia Ministry of Forests and Range soil scientists, we particularly want to acknowledge the input and guidance from Sharon DeHart1

, Sue Farley2, 

and Randy Davis3

. Countless reviewers, workshop participants, students, and technicians 

have tested this protocol and offered input on how to make it more user friendly. Their 

input has been extraordinarily beneficial.

1

 Former Soil Program Leader, Northern Region, Missoula, MT.

2

 Forest Soil Scientist, Helena National Forest, Helena, MT.

3

 National Soil Program Leader, Washington Office, Washington, DC.
vi Forest Soil Disturbance Monitoring Protocol

General Summary

This document—Volume II: Supplementary Methods, Statistics, and Data Collection—

defines the science, statistical methods, and data storage components of a national Forest 

Soil Disturbance Monitoring Protocol. This technical guide provides the basis for a consistent 

method with common definitions to produce high-quality data that land managers can 

access and use for decisionmaking. This volume, in conjunction with Volume I: Rapid 

Assessment, can be used to estimate forest management effects on the soil resource. 

Information gathered using this protocol can easily be conveyed to and used by the general 

public to describe soil disturbance classes before and after management. Volume III: 

Scientific Background for Soil Monitoring on National Forests and Rangelands, includes 

state-of-the-science papers from the proceedings of a workshop.
Volume II: Supplementary Methods, Statistics, and Data Collection 1

Introduction

Volume I and volume II of the Forest Soil Disturbance Monitoring Protocol (FSDMP) 

provide information for a wide range of users, including technicians, field crew leaders, 

private landowners, land managers, forest professionals, and researchers. Volume I: Rapid 

Assessment includes the basic methods for establishing forest soil monitoring transects 

and consistently monitoring forest sites before and after ground disturbing management 

activities for physical attributes that could influence site resilience and long-term sustainability. Volume II: Supplementary Methods, Statistics, and Data Collection provides more 

details on the protocol, the historical context of forest soil monitoring, the use of statistics 

in forest soil monitoring, and interpretation. 

Electronic Data Forms

As we improve the protocol, we periodically update the electronic data forms, which users 

can download from http://forest.moscowfsl.wsu.edu/smp/solo/documents/monitoring/forms/.

A database is being developed for storage of data collected using the FSDMP. Data 

recorded on the electronic field forms will be converted to database format and imported 

into the national FSDMP database when it becomes available. In the interim, the data 

should be kept locally and/or on regional servers.

Initially, the national FSDMP database will combine the features of two existing 

products—the Forest Service Rocky Mountain Research Station and the Northern Region 

SoLo database and Southern Region ONSITE disturbance calculator—and will ultimately 

be linked to or integrated with the Natural Resource Information System. 

SoLo is an online report filing system on the Northern Region computer system. It is 

accessible only on the Forest Service secure intranet (fsweb) and features user profile 

management, a secure login, keyword search capability, a data input interface, and data 

summary and export functions. The input interface is in seven parts: site identification, 

site location, site characteristics, site history, current activity and effects, summary/

conclusions, and administrative information.

ONSITE is a Microsoft® Access® database that is distributable on compact disc (CD) 

in either a user or an administrator version. It is designed for recording large areas of 

disturbance in an activity area. Within the database are forms to record site identification, 

location, physical characteristics, and soil disturbance types (loss/movement, alteration, 

fire) by area affected, plus a “Tally Sheet” that will calculate area based on the shape of 

the disturbance (circle, oval, rectangle, or triangle).
2 Forest Soil Disturbance Monitoring Protocol

Historical Context for Monitoring Forest Soils

Although many definitions describe what soil quality is, or should be, on public lands 

in the United States, maintenance of soil productive capacity is a common objective. 

Maintaining soil productivity and quality on National Forest System land is governed by 

the Multiple Use and Sustained Yield Act of 1969, the Forest and Rangeland Renewable 

Resources Planning Act of 1974, and the National Forest Management Act (NFMA) of 

1976. The important role of soil productivity to sustainable forestry is clear, but which 

soil properties to monitor as indicators of forest sustainability are not so clear (Burger and 

Kelting 1998, Page-Dumroese et al. 2000, Staddon et al. 1999). 

The challenge has been the development of meaningful soil quality standards to evaluate 

the full range of variability found in forest soils (Page-Dumroese et al. 2000). Many 

forest soils are resilient to management activities (e.g., timber harvests, hazardous fuel 

reductions, prescribed fire, and site preparation), while others are at risk of losing the 

productive capacity after vegetation management because of limitations in the inherent 

soil properties (e.g., shallow forest floor or thin mineral mantles over bedrock [Burger 

and Kelting 1999]). Therefore, establishing monitoring variables and protocols that are 

practical to use, give meaningful information over a wide range of sites, and provide a 

benchmark for evaluating soil change is critical (Page-Dumroese et al. 2000). Adequate 

baseline assessments of important site-specific properties such as forest floor depth, soil 

cover, and so on will help make accurate and realistic projections of potential site changes 

from management activities. NFMA (and related legislation) required the United States 

Secretary of Agriculture to ensure, through research and monitoring, that the national forests be managed to protect the permanent productivity of the land (USDA Forest Service 

1983). The Forest Service established the first approximation of working soil quality standards throughout the Federal regions (Page-Dumroese et al. 2000, Powers et al. 1998). 

The first approximation standards were meant as monitoring tools that were presumed to 

reflect site potential and to mark thresholds for significantly impaired productivity. 

The Forest Service program of the North American Long-Term Soil Productivity 

(LTSP) program was built on the principle that, within the constraints of climate, a site’s 

productive capacity is governed strongly by physical, chemical, and biological processes 

affected readily by management. The fundamental properties of soil porosity and site 

organic matter govern a site’s response to management by their roles in water and gas 

exchange, rooting restrictions, microbial activity, soil aggregate stability, and overall 

resource availability (Powers et al. 2005). These LTSP sites are now 15 years old and 

are beginning to reach crown closure. Numerous research papers have been published 

(e.g., Busse et al. 2006; Fleming et al. 2006; Page-Dumroese et al. 2006a; Sanchez et al. 
Volume II: Supplementary Methods, Statistics, and Data Collection 3

2006) detailing changes in site processes and tree growth. The LTSP study provides the 

calibrations to link the soil disturbances described within this document with changes in 

potential productivity.

Soil Disturbance

Soil quality is a moving target and our ideas of what it is and how to measure it have 

evolved over the years. Unfortunately, it cannot be measured directly (Powers et al. 

1998). The conundrum is to define the functional elements of soil that sustain biological 

productivity and to identify soil quality indicators of these functions (Powers et al. 1998). 

Useful indicators must be sensitive to variations in climate and management; integrate 

soil physical, chemical, and biological properties; and be practical and useable by a 

variety of disciplines. Therefore, defining the functional elements of soil that sustain biological productivity and identifying indicators of those properties are key to the success 

of monitoring. Useful indicators have been proposed for agricultural systems that have 

less spatial variability and more management intensity (Doran and Parkin 1994, Larson 

and Pierce 1994, Warkentin 1995) than are commonly found in forest soils (Burger and 

Kelting 1998). Because the processes and properties of forest soils are more varied and 

less well understood, a detailed, intensive approach (Doran and Parkin 1994) is probably 

not justified for monitoring forest soil quality extensively in the United States (Burger and 

Kelting 1998, Powers et al. 1998). 

Soil disturbance in forested ecosystems most commonly occurs from ground-based 

harvest and site preparation (mechanical and fire) activities, but it can also occur as sheet 

or rill erosion. After a review of the apparent evidence that soil productivity has declined 

under forest management (Morris and Miller 1994, Powers et al. 1990), changes in soil 

physical properties and organic matter content were noted as two factors that could alter 

soil quality, by changing the ability of roots to support leaf mass and primary productivity 

(Powers et al. 1998).

 The effects of soil disturbance on soil productivity, soil quality, or site hydrologic function are dependent on the degree, extent, distribution, and duration of the effects (Clayton 

et al. 1987, Craigg and Howes 2007, Froehlich 1976, Snider and Miller 1985). 

The degree and duration of soil disturbance effects are largely determined by inherent soil 

properties, such as texture, coarse-fragment content, or organic matter content. Extent, 

distribution, and, in some instances, degree of soil disturbance can be controlled by 

management constraints, such as changing the season of operation, spacing of skid roads, 

or the number of equipment passes. 

Soil Disturbance Effects 

on Productivity Are 

Determined by...

Degree refers to the 

amount of change in any 

one particular property 

(bulk density, porosity, etc.) 

and the depth of change 

into the soil profile. 

Extent refers to the amount 

of land surface affected by 

the disturbance (usually 

expressed as a percentage). 

Distribution of soil 

disturbance within a 

management area can 

either be relatively evenly 

dispersed throughout the 

unit in small polygons or 

be concentrated in one (or 

more) larger feature(s). 

Duration is the length of 

time disturbance effects 

persist.
4 Forest Soil Disturbance Monitoring Protocol

To monitor and quantify changes in soil properties that could have potentially detrimental 

effects on site productivity or hydrologic function, we need a consistent method to assess 

and report soil disturbance that occurs as a result of management activities. Simply stating that a single threshold beyond which detrimental soil conditions are thought to exist 

is neither practical nor desirable (Craigg and Howes 2007). Forest managers do not wish 

to degrade soil productivity or cause impaired watershed function, and they should not be 

unnecessarily limited in management opportunities (Craigg and Howes 2007).

The soil disturbance classification system described in this volume provides technical 

direction to enable effective communication of results to specialists and the public. It also 

provides for a comparison of operational results from one site to another. 

Our objectives for this volume are to recommend common terms for describing forest soil 

disturbance, detail a statistically sound technique for applying visual classes for routine 

forest soil monitoring, and provide reliable methods for classifying the effects of management.

Why Use Visual Classes?

Forest management activities all have the potential to create soil disturbances. Some soil 

disturbance may be beneficial if it is planned and conducted under suitable soil conditions 

by the proper equipment. The removal of forest floor material, displacement of the mineral 

soil, compaction, puddling, erosion, and high burn severity, however, can have potentially 

negative effects on site productivity and hydrologic responses. The Forest Service must 

be able to manage soil disturbance in order to maintain sustainable production of natural 

resources (Craigg and Howes 2007). 

Describing or defining soil disturbance in terms of variables such as soil strength, pore 

space, or bulk density makes assessing soil changes resulting from management activities 

difficult and expensive. Soil variability and variation in the pattern of equipment operations 

or burning activities further complicates assessments. Other factors such as climate (both 

macro- and micro-), vegetation management practices, genetics, and distribution of hazardous fuels can affect the extent and degree of soil disturbance and subsequent effects 

on site productivity. In addition, several forms of disturbance can occur in one location, 

adding to the complexity of the assessments. For example, forest floor removal, mineral 

soil displacement, and compaction often occur in the same location. In most forest soils, 

bulk density (the measure of compaction) increases with increasing depth. In soils where 

the topsoil has been displaced, the natural increase in bulk density could be confused with 

compaction. 
Volume II: Supplementary Methods, Statistics, and Data Collection 5

One way to simplify and standardize soil disturbance assessments is to use visual classes 

to describe the degree of change from natural or preactivity conditions to those resulting 

from management activities. Soil disturbance visual classes also enable soil scientists to 

more easily communicate desired soil conditions and display effects to members of the 

public, contract administrators, and other resource specialists. Soil disturbance occurs 

in a continuum over the landscape and the visual disturbance class method enables an 

observer to divide the continuum into meaningful, describable, repeatable segments. 

Regardless of which soil indicators are ultimately selected, they should be comparable to 

an available baseline, be timely, be applicable over a large area, and be inexpensive and 

easy to use (Burger and Kelting 1999). They should also provide an effective means for 

communicating the effects of land management on soil resilience and productivity.

Visual classes have been used by a variety of public and private entities (e.g., Block et al. 

2002, Craigg and Howes 2007, Curran et al. 2005, Heninger et al. 2002, Page-Dumroese 

et al. 2006b) for the assessment of change in soil disturbance from preactivity to postactivity. Visual classes offer a method to efficiently and consistently gather information 

about soil disturbance. Curran et al. (2007) report that visual disturbance categories provide a practical method for describing soil disturbances in a forested setting. Several soil 

scientists in the western United States (e.g., Craigg and Howes 2007, Curran et al. 2005,

Curran et al. 2007, Heninger et al. 2002, Howes et al. 1983, Page-Dumroese et al. 2006b) 

have conducted research on using visual indicators. The previous authors of visual indicator research provide additional background information on the visual indicators used in 

the FSDMP (table 1). Selection of these indicators is based on several field seasons of 

research and testing across the forested United States and collaborative work with the 

British Columbia Ministry of Forests and Range and published literature.

Forest floor 

impacted

Forest floor material includes all organic horizons above the mineral soil surface. 

Topsoil 

displacement

The surface mineral soil primarily includes the A horizons, but if the A horizon is 

shallow or undeveloped, it may include other horizons. This disturbance is usually 

due to machinery but does not include “rutting” described below.

Rutting Ruts vary in depth but are primarily the result of equipment movement. Ruts 

are defined as machine-generated soil displacement or compression. Often soil 

puddling is also present within the rut.

Burning (light, 

moderate, severe)

Burn severity includes only effects on the forest floor and mineral soil, not on 

above-ground vegetation.

Compaction Compaction by equipment results in either a compression of the soil profile or 

increased resistance to penetration.

Platy structure/

massive/puddled 

Platy or tabular structure in the mineral soil. Massive soil indicates no structural 

units are present and soil material is a coherent mass. Puddled soil is often found 

after wet weather harvest operations. Soil pores are usually smeared and prevent 

water infiltration.

Table 1.—Visual indicators and their definitions. 
6 Forest Soil Disturbance Monitoring Protocol

In this FSDMP, disturbance classes (table 2) are used as a proxy to determine whether 

observed soil disturbances could be considered detrimental to soil productivity or 

hydrologic function. Ideally, validation of vegetative response or changes in hydrologic 

function will occur for various soil types, logging practices, and forest types. After a soil 

disturbance class is determined at each sample point within an activity area, the information can then be aggregated to calculate how much detrimental soil disturbance exists 

in an activity area and what the amount and distribution of detrimental soil disturbance 

could mean for long-term productivity. 

Soil disturbance class 0

Soil surface:

•	 No evidence of compaction; i.e., past equipment operation, ruts,

skid trails. 

•	 No depressions or wheel tracks evident.

•	 Forest floor layers present and intact.

•	 No soil displacement evident.

•	 No management-generated soil erosion.

•	 Litter and duff layers not burned. No soil char. Water repellency

may be present.

Table 2.—Soil disturbance classes used in the Forest Soil Disturbance Monitoring Protocol. Soil disturbance classes increase in 

severity of impact from class 0 to class 3.

* Accessory items are those descriptors that may help identify individual severity classes.

Soil disturbance class 2 

Soil surface:

•	Wheel tracks or depressions are 5 to 10 cm deep.

•	Accessory*: Forest floor layers partially intact or missing.

•	Surface soil partially intact and may be mixed with subsoil.

•	Burning moderate: Depth of char is 1 to 5 cm. Accessory*: Duff

deeply charred or consumed. Surface-soil water repellency 

increased compared with the preburn condition. 

Soil compaction:

•	Increased compaction is present from 10 to 30 cm deep.

Observation of soil physical condition:

•	 Change in soil structure from crumb or granular structure to

massive or platy structure; restricted to the surface, 10 to 30 cm.

•	Platy structure is generally continuous.

•	Accessory*: Large roots may penetrate the platy structure, but

fine and medium roots may not.

•	Erosion is moderate.	

Soil disturbance class 1 

Soil surface:

•	 Faint wheel tracks or slight depressions evident and are <5 cm

deep.

•	 Forest floor layers present and intact.

•	Surface soil has not been displaced and shows minimal mixing

with subsoil.

•	Burning light: Depth of char <1 cm. Accessory*: Litter charred

or consumed. Duff largely intact. Water repellency is similar to 

preburn conditions. 

Soil compaction:

• Compaction in the surface soil is slightly greater than observed

under natural conditions. 

• Concentrated from 0 to 10 cm deep.

Observations of soil physical conditions:

•	 Change in soil structure from crumb or granular structure to

massive or platy structure; restricted to the surface, 0 to 10 cm.

•	Platy structure is noncontinuous.

•	 Fine, medium, and large roots can penetrate or grow around the

platy structure. No “J” rooting observed.

•	Erosion is slight.

Soil disturbance class 3 

Soil surface:

•	Wheel tracks and depressions highly evident with depth >10 cm.

•	Accessory*: Forest floor layers missing.

•	Evidence of surface soil removal, gouging, and piling.

•	Most surface soil displaced. Surface soil may be mixed with

subsoil. Subsoil partially or totally exposed.

•	Burning severe: Depth of char is >5 cm. Accessory*: Duff and 

litter layer completely consumed. Surface soil is water repellent. 

Surface is reddish or orange in places. 

Soil compaction:

•	Increased compaction is deep in the soil profile (>30 cm deep).

Observations of soil physical conditions:

•	 Change in soil structure from granular structure to massive or

platy structure extends beyond 30 cm deep.

•	Platy structure is continuous.

•	Accessory*: Roots do not penetrate the platy structure.

•	Erosion is severe and has produced deep gullies or rills.
Volume II: Supplementary Methods, Statistics, and Data Collection 7

Current Forest Soil Needs

The FSDMP was developed in response to a growing need for a common understanding 

of soil disturbance monitoring in forested settings. The protocol is designed to meet a 

wide range of needs, including project-level implementation or effects monitoring. The 

FSDMP is a rapid assessment tool that is easy to implement and is usable at different 

scales and intensities. In addition, because it is used in a consistent manner, data can be 

aggregated. The FSDMP was developed to address vegetation management effects to 

soil quality in forested ecosystems. Other monitoring protocols, such as the Monitoring 

Manual for Grassland, Shrubland, and Savanna Ecosystems (Herrick et al. 2005), are 

more appropriate for assessing the effects of management to soils supporting shrubland 

and grassland ecosystems.

Key Concepts 

The FSDMP is meant to be a rapid assessment of preactivity and postactivity soil 

disturbance that provides a consistent and repeatable method to describe visual physical 

soil indicators. It is intended for use by field soil scientists and watershed specialists, with 

broad application for other disciplines. Field soil scientists and managers can predetermine the types of information they need as they plan activities that cause soil disturbance 

and the subsequent need for monitoring projects. This protocol also offers an opportunity 

to consider what kinds of decisions will need to be made, how information will be used, 

what need exists for highly precise information (risk), and how much the monitoring 

effort will cost (Howes 2006). 

For use in forested settings, this monitoring protocol assesses soil surface disturbance. 

The protocol can be used to monitor preactivity and postactivity area disturbance and 

was designed to be flexible enough to be used following a variety of forest management 

practices on the full range of soil types. Some changes (such as compaction and rutting), 

however, are linked to an increase in that property at depth. Numerous equipment trips or 

deep ruts are often evidence of deep soil compaction, but not always. A shovel or metal 

probe may be needed to determine the actual depth of compaction.

Sampling protocols similar to this have been used in Forest Service Regions 1 and 6 for 

both research and operational studies. They have been used to monitor the effects of soil 

compaction on initial height growth of ponderosa pine (Cochran and Brock 1985), the 

effect of feller-bunchers on soil disturbance (Laing and Howes 1988), and the effect of 

tractor yarding and machine piling on 24 timber sales (Sullivan 1987) and to determine 

the effects of wildfire and salvage logging on soil disturbance on all the national forests 

Rapid Assessment

The FSDMP provides for 

a variety of alternatives 

to suit the monitoring 

objective. You can—

1. Vary the intensity of 

sampling by changing 

the confidence level,

2. Vary the number of 

soil attributes used 

for calculating sample 

size, and/or

3. Use ONSITE to calculate the areal extent 

of large features.
8 Forest Soil Disturbance Monitoring Protocol

in the Forest Service Northern Region (Page-Dumroese et al. 2006b). In addition, similar 

visual class systems are being used in British Columbia (Curran et al. 2005) and Saskatchewan (Block et al. 2002). Information gathered from these monitoring efforts can be used 

to adjust harvest and site preparation practices (Howes 2006). 

Because the results of management activities on soil productivity vary by soil type (Fleming 

et al. 2006, Gomez et al. 2002, Page-Dumroese et al. 2000, Page-Dumroese et al. 2006b, 

Powers et al. 2005), this document does not prescribe any disturbance class as detrimental 

disturbance. The FSDMP establishes a standard inventory, monitoring, and assessment tool. 

In addition, it provides common terms. Storing data in the SoLo database (see appendix C 

for a description of the FSDMPSoLo monitoring worksheets) will allow for consistent 

data interpretation at local, regional, and national levels and will facilitate data sharing. 

Monitoring results can also help determine if current Forest Service Regional Soil Quality 

Standards are being met.
Volume II: Supplementary Methods, Statistics, and Data Collection 9

Relationship to Other Federal Inventory and 

Monitoring Programs

This volume of the FSDMP presents a protocol for field measurement of physical soil 

disturbance. The protocol is for site-specific analysis of management-induced soil disturbance in an activity area (e.g., a harvest unit or prescribed burn). This protocol differs 

from other Forest Service or other Federal agency monitoring programs because it is 

designed to collect site-specific data at the project level.

Programs in Other Federal Agencies

The Natural Resource Conservation Service (NRCS) leads the national soil survey program. This program is a mid-scale soil mapping and characterization project that informs 

field soil scientists as they plan their workload for site-specific forest management projects. Nationwide, many national forests have or are working toward having a soil survey 

completed for the forest, excluding wilderness areas.
10 Forest Soil Disturbance Monitoring Protocol

Changes to the Current Protocol 

(Change Management)

Volumes I and II, which detail the FSDMP, are dynamic documents; changes to the 

outlined protocol are inevitable as sites are monitored and data are analyzed. Changes 

to the protocol must be carefully considered, however, so that the objective of having 

a consistent approach to obtaining physical soil data is met. New science related to soil 

monitoring or management effects may initiate a review and suggest changes to this 

protocol. Changes to the FSDMP can also be initiated from the field, but they must be 

subject to peer and research review. In addition, collaborations with industry, private, 

tribal, and international land management organizations could lead to the development of 

other soil disturbance monitoring and conservation procedures. These collaborations will 

allow for continuous evolution of best management practices, enable coordinated development of training and tools, facilitate reporting, and enhance the exchange of research 

results (Curran et al. 2005). 
Volume II: Supplementary Methods, Statistics, and Data Collection 11

Determining the Type of Transect To Use

Transects can be positioned in a variety of ways within the activity area. Three examples 

are outlined in appendix A.
12 Forest Soil Disturbance Monitoring Protocol

Stratifying an Activity Area

As outlined in volume I, many monitoring strategies are available. Because of site variability, it can be useful in some cases to stratify an activity area to increase monitoring 

efficiency and to provide better estimators when there are discrete areas of homogeneous 

disturbance. For example, disturbance may be confined to one area or it could be dispersed across the entire activity area. Stratifying an activity area may help improve both 

the accuracy and precision by finding the most efficient monitoring polygons. Monitoring 

efficiency is defined as resulting in lower variability estimates than would have been 

achieved without stratification.

If the Unit Is Large 

It may not be feasible to monitor a large activity area (100 ha (~250 acres or more) in its 

entirety. As noted in the following text, however, a large area can be stratified into more 

discrete units to make monitoring more efficient. Use the following options as a guide to 

help determine the most appropriate monitoring strategy. 

• Complete a rapid assessment of the entire activity area and take a minimum of 30 

sample points. This option is recommended if the activity area is uniform relative 

to the soils, vegetation, slope, and aspect. 

• If the activity area is not uniform ecologically or in terms of disturbance (e.g., 

different habitat types, sensitive soils, log decks, skid trails), it is recommended to 

stratify the sample. Stratification will allow for detailed monitoring on areas that 

have had previous entry; have mechanical, ground-based equipment off system 

roads; or are ecologically sensitive. As long as the point samples are collected at 

random or systematically (see appendix A for options on how to lay out sample 

points) and are based on the established protocols, the statistics of this subsample 

will be valid. The key is to document what was monitored and why.

Activity areas may not need a large number of sample points if the amount of variability 

is low. The number of monitoring points needed depends only on the variability within 

the activity area and not on its size. Validation monitoring completed in the Northern 

Region suggests that sample points spaced ~20 m (~65 ft) apart were close enough to 

determine the variability within activity areas that were ~50 ha (~125 acres) in size 

(Page-Dumroese et al. 2006b). 
Volume II: Supplementary Methods, Statistics, and Data Collection 13

The Number of Activity Areas To Monitor

It is important to consider how the data are going to be used, what the soil disturbance 

risk is, and what the variability of the individual activity area and analysis area are when 

determining how many areas to monitor. Use the FSDMP on enough activity areas 

within an analysis area so it is possible to interpret ratings for existing and detrimental 

disturbance and for mitigations, monitoring, or restoration prescriptions. If past monitoring or research demonstrates that similar activities, under similar climatic conditions and 

management, have resulted in disturbance levels well within the accepted maximum, then 

it is sufficient to visit the site and confirm that this is a typical activity area.
14 Forest Soil Disturbance Monitoring Protocol

Unique Monitoring Strategies

Monitoring points may fall on unusual features such as on large boulders, in down wood, 

under fallen trees or “tip-ups,” on stumps, within bushes, and in stream beds. If such 

monitoring points occur, you can offset a small distance from the transect line. Plan 

before you leave the office for what rules you will use to offset from unusual features. 

For instance, you may want to decide that offsetting 1 m (3 ft) west from any feature is 

appropriate, or you may decide that if a point falls on an unusual feature, it will be listed 

as “did not count.” Because the FSDMP assesses soil surface condition, it is important 

to note what the soil surface is. If you cannot assess the disturbance at or near a point 

because of obstacles (rocks, downed wood, stumps, etc.), record the presence of the 

obstacle(s), but then indicate “did not count” in the comment field and exclude that point 

from the data analysis by entering a period (.) in the cell for each indicator. Do not record 

either a “1” (present) or a “0” (absent) for any indicator at that point and do not leave a 

blank space. Keep in mind, however, that on some sites it is “normal” to have a larger 

number of surface rocks. If this condition is the case, a monitoring point falling on this 

feature should be counted.

Wildfire 

Wildfires are not assessed with this protocol. This protocol is designed to describe land 

management activity effects to the soil resource. 

Prescribed Fire or Burn Piles 

The effect of these management activities is considered in the FSDMP. These types of 

burns may or may not be detrimental to subsequent vegetative growth. Guidelines for 

assessing prescribed burn intensity are contained in the disturbance class definitions 

(table 3).

Disturbance 

type

Severity class

0 1 2 3

Equipment impacts

Past operation None. Dispersed. Faint. Obvious.

Wheel tracks or 

depressions

None. Faint wheel tracks 

or slight depressions 

evident (<5 cm deep).

Wheel tracks or 

depressions are >5 cm

deep.

Wheel tracks or 

depressions highly 

evident with a depth 

being >10 cm.

Table 3.—Examples of soil visual indicators and management activities. (1 of 2)
Volume II: Supplementary Methods, Statistics, and Data Collection 15

Disturbance 

type

Severity class

0 1 2 3

Table 3.—Examples of soil visual indicators and management activities. (2 of 2)

Equipment trails

from more than 

two passes 

None. Faintly evident. Evident, but not heavily

trafficked.

Main trails that are 

heavily used.

Excavated and

bladed trails1

None. None. None. Present.

Penetration 

and resistance2

Natural

conditions.

Resistance of 

surface soils may 

be slightly greater 

than observed under 

natural conditions. 

Increased resistance

is concentrated in the 

surface (10 cm).

Increased resistance is

present throughout the 

top 30 cm of soil.

Increased resistance

is deep into the soil 

profile (>30 cm).

Soil structure Natural

conditions.

Change in soil 

structure from crumb 

or granular structure 

to massive or platy 

structure in the surface 

(10 cm).

Change in soil structure 

in the surface (30 cm).

Platy (or massive)

structure is generally 

continuous. On older 

sites, large roots may 

penetrate the platy 

structure, but fine and 

medium roots may not.

Change in soil 

structure extends

beyond the top 

30 cm. Platy (or

massive) structure is

continuous. On older 

sites, roots do not 

penetrate the platy 

structure.

Displacement

Forest floor None. Forest floor layers 

present and intact.

Forest floor layers 

partially intact or missing.

Forest floor layers 

missing.

Mineral soil None. Soil surface has not 

been displaced and 

shows minimal mixing

with subsoil.

Mineral topsoil partially 

intact and may be mixed

with subsoil.

Evidence of topsoil

removal, gouging, 

and piling. Soil 

displacement has 

removed most of the 

surface soil. Surface 

soil may be mixed with

subsoil or subsoil may 

be partially or totally 

exposed.

Erosion None. Slight erosion evident 

(i.e., sheet erosion3

).

Moderate amount of 

erosion evident (i.e.,

sheet and rill erosion3).

Substantial amount 

of erosion evident. 

Gullies, pedestals, and 

rills noticeable. 

Burning None. Fire impacts are 

light. Forest floor is 

charred but intact. 

Gray ash becomes 

inconspicuous and 

surface appears lightly 

charred to black. 

Soil surface structure 

intact.

Fire impacts are 

moderate. Litter layer

is consumed and 

humus layer is charred 

or consumed. Mineral 

soil not visibly altered, 

but soil organic matter 

(OM) has been partially

charred.

Fire impacts are deep. 

The entire forest floor 

is consumed and top 

layer of mineral soil is 

visibly altered. Surface 

mineral structure and 

texture are altered.

Mineral soil is black 

due to charred or 

deposited OM or is 

orange from burning.

1

 Evaluate on main trails but not necessarily for wheel tracks or depressions.

2

 Soil resistance to penetration with a tile spade or probe is best done when the soil is not moist or wet.

3

 USDA NRCS (1993).
16 Forest Soil Disturbance Monitoring Protocol

Unburned Slash Piles 

Unburned or partially burned slash piles can be found on former landings, on skid roads, 

or in the previously harvested activity area. When these features are on landings or skid 

roads, they should be assessed as part of those structures because the underlying soil 

will probably be similar to the surrounding affected area. Similarly, if an old slash pile 

is located in the harvest activity area, it is likely that the soil beneath the pile could be 

affected to the same degree as the surrounding soil. It is often difficult to examine the 

soil beneath some slash piles, however, so if an inference is made about the soil beneath 

the slash pile from the surrounding soil, a note should be made in the comments. If a 

confident prediction cannot be made about the soil under a slash pile, then indicate “did 

not count” on the Data entry worksheet (see appendix C-3).

Landings, Temporary Roads, and System Roads 

System roads generally are not included in the activity area. System roads are part of the 

permanent transportation system and the land has been removed from the productive land 

base. 

• Landings and temporary roads that are outside the activity area are not included. 

Landings and temporary roads usually limit vegetative growth by their very nature. 

If desired during monitoring, an acreage (length times average width based on a 

traverse study, aerial photo, or ONSITE worksheet) of these features can be kept if 

needed for existing condition, project effects, and cumulative effects discussions. 

• Landings and temporary roads that are inside the activity area are counted and 

contribute to the amount of disturbance within an activity area. In addition to recording 

the disturbance class of these features, acreage (length times average width based 

on a traverse study, aerial photo, or similar method) of these features can be 

recorded to describe the existing condition, project effects, and cumulative effects. 

Root Ball or Bole of a “Tip-Up” 

If a monitoring point lands on the root ball or bole of a fallen tree, it is counted as coarse 

wood with a remark in the comment section stating “roots of fallen tree” or “tip-up.” If the 

reason for the tree tip can be determined, it should be noted. If the tree tip can be associated 

to human activity and a monitoring point falls on it, then that point is assigned a disturbance 

class based on what is observed immediately adjacent to the monitoring point. If the tree 

tip is not associated with human activity, the monitoring point is assigned class 0.
Volume II: Supplementary Methods, Statistics, and Data Collection 17

Examples of the four electronic worksheets used for the FSDMP are shown in appendix C 

(SoLo Info, Variable Selection, Data Entry, Results) and we provide an Attachment worksheet for uploading maps, photos, or other important site information (form not shown). 

As we endeavor to improve these methods, these worksheets may change. Check the following Web site for the most recent version before starting work in the field: http://forest.

moscowfsl.wsu.edu/smp/solo/InfoPath/monitoring/documents.php (look in the “FORMS” 

section). The worksheets were designed so forest soil monitoring consistently evaluates 

a standard set of soil disturbance indicators; this is the rationale behind having to fill out 

each column completely before moving on to the next monitoring point. Do not modify 

the field form; the field form was also designed to make data entry into the electronic 

database quick and easy. Storing the data in an electronic database is part of the FSDMP. 

Paper Field Form

Field data can be collected on paper field forms and then transferred into the electronic 

spreadsheet. Do not modify any of the worksheets within the spreadsheet as they will 

directly link to the electronic database. You can select the soil attributes you need, but 

do not change any of the fields. All data collected, whether on paper or electronic forms, 

should be entered into the FSDMPSoLo database. 

When using the paper field form, use the sample size table (see appendix D for both the 

paper field form and the sample size tables) must also be used. Users should stop at the 

end of the first 30 monitoring points and calculate the proportion of disturbed points 

within the first 30 by adding the number of “1s” entered and then dividing by 30 (see 

appendix B for the statistics behind the FSDMP). This proportion is pˆ and should be 

entered in the column labeled visual class proportions. The visual class proportion must 

then be located in the sample size table along with the associated sample size. Determining the sample size can be done for each indicator variable in the Data Entry form (see 

appendix C-3) or for the indicator that is the primary concern. Of primary interest are the 

most commonly occurring indicators. After the sample size is determined for each indicator variable, the largest sample size from the list of monitoring attributes should be used 

for the activity area sample size. An exception to this rule could occur if a single indicator 

variable is more variable than all the others, resulting in one sample size being much 

greater than all the rest (where “much greater” is defined as being more than 1.5 times the 

sample size of the next lower sample size) and the professional judgment of the observer 

is such that the indicator variable in question is not representative of the activity area and/

Spreadsheet Forms 
18 Forest Soil Disturbance Monitoring Protocol

or a concern on that soil type. In this case, the next lower sample size should be selected 

and a thorough explanation must be made in the comments.

It should be noted that the sample sizes calculated from the first 30 points are likely to be 

different from those calculated from a greater number; varying the intensity of the sample 

(lowering the confidence interval) may reduce the total number of sample points needed. 

The observer is free to choose some number higher than 30 for the first set, which may 

be more efficient if it initially appears that the soil disturbance within an activity is highly 

variable. The observer can also recalculate the sample size a second time if the initial 

sample size is quite large. 

Portable Data Recorder and Electronic Field Form

It is recommended that all data be entered into an electronic database that is searchable by 

any ecological state, location, characteristic, or activity. To use the electronic Data Entry

worksheet (see appendix C-3) in a portable data recorder (PDR) (see appendix F), the 

user must enter the confidence level. Although the full range of confidence levels is available (from 70 percent to 90 percent), each site should be assessed individually to select 

the best one. All columns for data entry must be filled in. Do not leave blanks within 

the form, or the sample sizes and confidence intervals will be incorrect. We recommend 

filling out the columns for each sample point as the point is actually observed. If a point is 

not observable, fill in the column for that point with periods (.) and document the reason 

why the point “did not count” (see the Unique Monitoring Strategies section for definitions). DO NOT FILL IN THESE POINTS WITH ZEROS. 

The electronic spreadsheet (on the Data Entry worksheet; see appendix C-3) calculates 

sample size and confidence intervals automatically and updates each additional monitoring point (on the Results worksheet; see appendix C-4); however, until the first 30 

monitoring points are entered, the values for sample size are preset to 30 and confidence 

intervals are invalid. It is important to note that if the worksheet is prefilled with zeros, 

the sample sizes and confidence intervals are likely to reflect an inaccurately low level of 

variability and are likely to be incorrect.

The required sample size shown on the electronic spreadsheet is the largest of the sample 

sizes calculated for the individual indicator variables. The individual sample sizes can be 

seen by changing to the Results worksheet (see appendix C-4). If the required sample is 

more than 1.5 times larger than the next lower sample size and the professional judgment 

of the observer is that the indicator variable is an anomaly within the activity area, the 

next lower sample size can be chosen and a thorough explanation made in the comments.
Volume II: Supplementary Methods, Statistics, and Data Collection 19

Field Data Collection—Standards and Methods

The core soil disturbance indicators (table 1) should be collected at each monitoring 

point, but the user has the ability to “turn off” soil indicators (changing the number of 

indicators) that do not pertain to the project area being monitored (see Variable Selection

worksheet, appendix C-2). After the soil indicator data have been collected, additional 

data can also be collected using other published protocols (e.g., bulk density or soil 

hydrophobicity). When using other protocols, document what they are and on which sites 

they were used.
20 Forest Soil Disturbance Monitoring Protocol

Filling in the Worksheets

Data To Collect in the Office

Before beginning a field evaluation of soil disturbance on an activity area, available existing information sources should be studied and applicable information should be recorded 

the SoLo Info worksheet (see appendix C-1) and additional information on these site 

descriptors can be found in appendix G. Time spent in the office gathering information 

before field sampling and determining the kind of transect, the number of points, and the 

indicators needed can reduce field time and monitoring costs.

In general, the following steps should be followed before going in the field:

1. Consult the most current subsection map (McNab et al. 2007) and available 

landtype association maps for general site characteristics. The SoLo database may 

require some of this information, which can help stratify the area for sampling. It 

is important to note, however, that such broad-scale maps are not appropriate for 

the more detailed site information needed to assess soil quality.

2. Consult available soil surveys and terrestrial ecological unit inventories (TEUIs) 

for more detailed site information and for the description and morphology of the 

soils that occur in the project area. Soil surveys may have been done by the Forest 

Service or by the Natural Resources Conservation Service (NRCS) and may 

be referred to as soil resource inventories, TEUIs, or landtype inventories. This 

information can help establish soil reference conditions for the activity area. It is 

critical, however, to confirm the actual soil type after you are in the field.

3. Check previous field review and soil monitoring reports and use available data.

4. For postactivity assessments, consult the harvest plan and contract information to 

determine where existing skid trails, landings, or changes in harvest operations 

may have occurred.

Selecting Indicators

The indicators in the Variable Selection spreadsheet (see appendix C-2) are those that 

most closely align soil quality standards, data from research studies, and previous visual 

guide information. You may want to use some or all of these for preactivity and postactivity monitoring. After the monitoring objective has been set (see the following section), 

select the indicators, the transect configuration, and the confidence levels to meet those 

objectives. 
Volume II: Supplementary Methods, Statistics, and Data Collection 21

Some monitoring considerations include the timing of postactivity monitoring. Monitoring 

an activity area within 1 year of completion will provide answers related to the harvest 

or postharvest activities. Monitoring an activity area 3 to 5 years after completion will 

provide an indication of how resilient the soils are and the short-term duration of the 

disturbance. Some disturbance, however, will be much less visible after 1 to 2 years, particularly small-scale features in areas where litterfall is significant. Longer term monitoring 

is often not feasible in this context and studies such as The North American Long-Term 

Soil Productivity Experiment: Findings From the First Decade of Research (Powers et al. 

2005) will provide answers to long-term effects of soil disturbance on vegetative growth. 

Monitoring Objectives

For monitoring to achieve the goal of detecting change, it must be performed both before 

and after an activity. Each of these events, within the context of a rapid assessment, 

serves a different purpose. If field time is limited, using the FSDMP in conjunction with 

ONSITE (areal extent of large features) can help get the most relevant information that 

can be transferred to similar sites. Data that are collected in the same way and that use the 

same indicators ensure that you can match data and sites. 

Using a preactivity assessment will provide a baseline or reference condition against 

which change or disturbance can be measured. On sites known to be undisturbed—that is, 

have never been affected by human enterprise—only minimal assessment may be necessary. On these undisturbed sites, simply fill out the form in appendix E.

 On sites known to be previously disturbed, a low-intensity rapid assessment can be used 

to reveal the location and extent of a previous disturbance, which will be useful in planning and estimating cumulative effects. Information can be gleaned from previous project 

reports and stand histories, and, depending on the variability seen on these sites, a formal 

30-point-minimum assessment using the FSDMP may be recommended.

Step-by-Step Field Survey Method 

The steps to follow for a Rapid Assessment are explained in Vol. I.; the key information 

and steps are also listed here. For the FSDMP, the monitoring point of soil surface 

disturbance is taken in a 15-cm (6-in) diameter circular area (a “toe-point” assessment). 

By using the sample size calculator and appropriate confidence level, the project area 

can be adequately assessed using the circular point for disturbance classes. The visual 

disturbance category is chosen by selecting the one best fitting the monitoring point. 
22 Forest Soil Disturbance Monitoring Protocol

As the activity area is walked, each monitoring point along the transect or at each grid 

point is placed in one of the predefined classes (table 3). The monitoring point may 

represent soil attributes from more than one classification, and the soil scientist or other 

observer may have to make a decision about which visual disturbance class best describes 

the sample point. This protocol is to be used where activity areas are defined and discrete. 

For assessment of areas in a watershed context, without defined and discrete units, see the 

section titled “Unique Monitoring Strategies.”

Baseline (Preactivity) Assessment

Step 1. Prework—Determine why you are monitoring (goals) and if the FSDMP is 

the most efficient method for accomplishing those goals. As noted in the section titled 

“Data To Collect While in the Office,” fill out as much of the electronic or paper form 

as possible using existing documentation and interviews with other team members (see 

also appendix G). Inspection of topographic maps and areal photography can reveal basic 

landform information, such as slope and drainage patterns that affect soil productivity or 

hydrologic function. Select the variables you want to use for monitoring the activity area 

(see the Variable Selection worksheet, appendix C-2). Determine the size of the activity 

area. Determine which option for monitoring point layout will work best for your site (see 

appendix A). If choosing a random transect, select the length of transect needed and the 

distance between points. If choosing a grid point survey, select a random orientation for 

the grid points. If using an electronic PDR, predetermine grid point locations and save 

them onto the recorder.

Step 2. Select the Data Entry worksheet (see appendix C-3). If past ground-disturbing 

activities (e.g., stumps, skid trails, roads, differences in vegetation age or composition, 

or trash) are evident, continue to use the FSDMP for a quantitative estimate of the 

amount and extent of disturbance. Often, aerial photos and other maps can be used to 

determine the extent of effects. Field verification of compaction, displacement, or change 

in hydrologic state is necessary on sites with legacy effects. From preactivity assessments, 

determination of cumulative effects may be facilitated. Conversely, if records of previous 

management resulted in minimal soil disturbance and the activity area has similar soils, 

vegetation, aspect, and slope throughout the unit, then space a minimum of 30 monitoring 

points to cover the entire unit. When using the sample size calculator and appropriate 

confidence level, more points may be necessary. Take note of preactivity forest floor 

depth and composition, mineral soil horizon depth(s), and depth to bedrock (if applicable).

Step 3. Document a preactivity starting point using a Global Positioning System or other 

method of precise point location documentation. Using the sampling scheme selected 
Volume II: Supplementary Methods, Statistics, and Data Collection 23

from step 1, start sampling 5 m (~15 ft) inside the unit to avoid edge effects. If using a 

PDR (see appendix F), upload a map of the site and add predetermined monitoring point 

locations before going into the field. Predetermining monitoring point locations can also 

be done with paper copies of available maps.

Step 4. After locating the starting point within the activity area, calculate the distance 

between points based on activity area size. To avoid bias, sample point distances must 

be predetermined and documented before starting. Points must be evenly spaced to cover 

the entire activity area. For instance, if the activity area is ~1,000 m (3,300 ft) long and 

you need to take 30 sample points, points should be at least 35 m (110 ft) apart along the 

random transect. If the transect (or point grid) does not adequately cover the range of 

variability, then take more transects (or grid points) to confirm the presence or absence of 

dispersed disturbance and the nature of the dispersed disturbance. 

Step 5. Walk to the first point and assess the soil surface condition using the Data Entry 

worksheet (see appendix C-3). On the data form, record a “1” if the indicator is present 

and a “0” if the indicator or statement is absent, ending with a general Soil Disturbance 

Class (using table 3). For assistance with visual class determinations, use the Soil Disturbance Field Guide (Napper et al. N.d.). Continue collecting data at each monitoring point 

along the transect (grid). When you reach the edge of the activity area, select another 

transect direction (a predetermined grid point sampling scheme should be placed entirely 

within the activity area boundary) at an appropriate angle (toward the inside of the activity area) from the previous transect and continue data collection on the same spreadsheet. 

Note that, as you make observations at each monitoring point, the required sample size 

will likely change as the estimated variability changes. 

Step 6. Continue the assessment until you reach the appropriate sample size. On the 

data form, record a “1” if the indicator is present and a “0” if the indicator or statement 

is absent, ending with a general soil disturbance class (table 2). Take AT LEAST 30 

monitoring points in the activity area that has disturbance. Use aerial photos, ONSITE, 

or activity area maps to measure temporary roads and landings within or contiguous to the 

activity area, but take additional notes. Estimate disturbance on temporary roads or landings not in the activity area separately and manually add after completing this method.

Step 7. Use the comment field at the bottom of each column (or a field notebook) to document noteworthy existing disturbance. Use these comments to document unusual spatial 

features related to the disturbances or to record the type and severity of erosion features.

Step 8. In the last row of the Data Entry worksheet (see appendix C-3) indicate if the soil 
24 Forest Soil Disturbance Monitoring Protocol

disturbance is detrimental. This row of information is based on the professional judgment 

of a qualified soil scientist, literature, or other local studies. 

Postactivity Assessment

Step 1. Before starting work in an activity area, examine the soil in a nearby undisturbed 

unit for forest floor thickness, composition, mineral soil horizon depth(s), and depth to 

bedrock (if applicable). If baseline data have been collected (as in baseline assessment 

step 2), then this examination procedure may not be necessary. Examining an undisturbed 

area is essential, however, if one observer recorded the preactivity data and another 

observer is collecting the postactivity data. If an undisturbed site is not available, examine 

the undisturbed soil around stumps to become familiar with uncompacted soil conditions. 

Decide on the type of monitoring transect needed and locate a starting point using a 

method similar to that used for the preactivity assessment. It is not necessary to replicate 

transect locations from the previous assessment. The required sample size is likely to 

be different because of the increased variability of the site postactivity. It is better to 

complete two different assessments within the activity area.

Step 2. Using the procedure described for preactivity assessments, determine the soil 

surface disturbance. Record data points until you have taken enough monitoring points 

to reach the sample size calculated by the electronic spreadsheet or shown on the paper 

sample size table. 

As in steps 7 and 8 (in the preactivity assessment), indicate the disturbance class for 

each point and indicate which points are considered detrimentally disturbed and would 

affect long-term site sustainability.
Volume II: Supplementary Methods, Statistics, and Data Collection 25

Interpreting the Results

Examples of questions that can be answered based on preactivity and postactivity soil 

disturbance assessments include the following: 

1. How does soil disturbance differ from preactivity to postactivity?

2. What on-the-ground effects have resulted from the activity?

3. How do project effects compare to the effects predicted in the planning document?

4. Were soil mitigation measures implemented as planned and were they successful?

5. How does postactivity disturbance compare to the desired condition disclosed in 

the forest plan?

6. What mitigation measures would move soil resource conditions toward forest plan 

standards?

7. How and why did the soil disturbance classes change?
26 Forest Soil Disturbance Monitoring Protocol

Site Attributes

The following site attributes are entered into the electronic worksheet labeled SoLo Info

(see appendix C-1). These site attributes are inserted into the worksheet during the “in the 

office” phase. Site attributes are described in detail in appendix G.

Soil Texture 

Soil texture is a key property and allows for preassessment site stratification and later 

stratification of data results. Soil texture information is obtained from field examination. 

Although published soil surveys can be valuable resources, this information is often 

collected over too broad of a landscape and includes too many inclusions for site-specific 

assessment. Soil survey information needs to be verified in the activity area. Use standard 

techniques for identifying soil texture classes. The NRCS Field Book for Describing and 

Sampling Soils provides soil texture class definitions and techniques for classification 

(Schoeneberger et al. 1998). Soil texture information is recorded as sand, sandy loam, silt, 

loam, clay, and so on (as per the textural triangle). Soil texture often changes with depth 

and it is important to note these changes, particularly when describing soil displacement 

and erosion.

Soil moisture is critical when interpreting soil resistance to penetration as an affect of 

soil compaction. Record the soil moisture as dry, moist, or wet in the comment field of 

the SoLo Info worksheet. Dry soils have little to no moisture when examined in the field; 

in contrast, wet soils are saturated or nearly saturated and you can squeeze water out 

of them. Soil strength generally increases as the soil dries, so care must be taken when 

evaluating a soil for compaction if the soils are very dry. For example, a clayey soil can 

be very hard when dry, even if it is not compacted. Also, in some soils, massive structure 

may be more related to soil moisture than soil compaction from equipment operations. 

Note that compacted soils often stay moister longer than uncompacted soils, so, if clay is 

present, there could be a difference in penetration resistance related to the clay, not just 

compaction. 

Information on coarse fragment percentage, size, and distribution within the surface soil 

is important when prescribing mitigation and restoration techniques. This information 

can be obtained from the local soil survey and verified in the field. Coarse fragments also 

determine the sensitivity of the soil to disturbance or its resiliency. The coarse fragment 

percentage class is categorized as <15% coarse fragments (no modifier, use the dominant 

texture), 15 to <35% (gravelly), 35 to <60% (very gravelly), 60 to <90% (extremely 

Definitions of Attributes and Indicators
Volume II: Supplementary Methods, Statistics, and Data Collection 27

gravelly), >90% (no modifier, use the dominant size class; e.g., gravel). The size of coarse 

fragments is described as gravel (2 to <75 mm), cobble (75 to <250 mm), stone (250 to 

<600 mm), or boulders (>600 mm). The location of the coarse fragments is described as 

being mixed throughout the surface soils, limited to the A horizon, or limited to the B 

horizon or deeper (as estimated during a shovel test). 

Textural class information does not need to be collected at every sample point but does 

need to be collected frequently enough to describe the heterogeneity or homogeneity of 

the activity area. The information on surface and subsurface texture is collected as a note 

and recorded on the SoLo Info worksheet (see appendix C-1). 

Vegetation 

Describing the vegetation provides insight about effective ground cover, changes in site 

productivity, and how well plants are using the soil resource. In the SoLo Info worksheet 

you can record the overall vegetation type (habitat type) and note any invasive or special 

species on the site. Information about the presence or absence of vegetative cover can 

be recorded at each sample point if desired. In addition, if a soil pit or other soil survey 

methods are used, information about root depth, location, abundance, and density can be 

recorded (Schoeneberger et al. 1998). These values can be collected for the activity area, 

along the transect (or grid points) at predetermined sample points (e.g., every 10 points) 

or when vegetation characteristics change.

Soil Structure 

Soil structure is the naturally occurring arrangement of soil particles into aggregates. Most 

soil descriptions will include a note about structure (massive, granular, blocky, crumb, 

etc.) (Schoeneberger et al. 1998). Mechanical site treatments or prescribed fire may 

reduce these aggregates into smaller particles by the removal of organic matter or physical crushing. Mechanical treatments may also cause the structure to become massive (no 

structural units; material is a coherent mass) or puddled (soil smeared by machine traffic 

during wet conditions). The smaller particles created by physical crushing may alter infiltration, water and gas exchange, and biological processes. Although this site characteristic 

is often associated with the soil textural class, it can also be altered by harvest or site 

preparation activities. Overall, soil structure as related to the activity area and changes due 

to management should be noted on the SoLo Info worksheet (see appendix C-1). 

Activity Area History 

The attribute values for active area history are inserted into the SoLo Info worksheet and 

are collected once for each activity area when data are available. If these data are unavailable, insert a period (.) into the field. Providing activity area history also provides context 
28 Forest Soil Disturbance Monitoring Protocol

for soil data interpretation. The values are collected once for every activity area. This 

information can be filled in during an office exercise before the field visit. 

Soil Indicators

Soil indicators in the FSDMP were selected because they are fairly robust, could be used 

on a variety of sites, and are easy to define and recognize. Indicators can be turned “on” 

or “off” in the Variable Selection worksheet (see appendix C-2). All information about 

the following indicators is recorded as either a “1” (present) or a “0” (absent) on the Data 

Entry worksheet (see appendix C-3) within the 15-cm (6-in) sample point area. Figure 1 

illustrates a harvest area with minimal soil surface effects. 

Figure 1.—Harvested stand with areas of class 0 disturbance.

Machine Traffic Disturbances

Compaction and Bulk Density. The Data Entry worksheet (see appendix C-3) has 

three rows in which compaction are listed (by depth). Determine the maximum extent 

of compaction and record a “1” (present) in the appropriate cell for that sample point. 

The other two rows each will receive a “0” (absent). Indicators of change in compaction 

level are past operations (from aerial photos or databases), wheel tracks or depressions 

(ruts), equipment trails from more than two passes, excavated or bladed trails, penetration 

resistance, and a change in structure.
Volume II: Supplementary Methods, Statistics, and Data Collection 29

A metal rod or shovel can be inserted into the ground to determine changes in the compaction level of a sample point. This surrogate for bulk density sampling can be effective 

if undisturbed soils are nearby to calibrate this “push” test. All observers must calibrate 

themselves to the physical resistance of each soil type. Although a change in compaction 

is often measured by pushing a rod or spade into the soil (or taking a bulk density core), 

the visual attributes listed previously (wheel tracks, equipment trails, etc.) may be all that 

is necessary to determine a change in surface disturbance. 

Placing compaction into a soil disturbance class—a 1, 2, or 3 (table 3)—is based on depth 

of compaction change into the mineral soil. Because of this depth relationship to the soil 

disturbance classes, it is important to know the undisturbed condition (at depths) of the 

soil preactivity.

Rutting and/or Wheel Track Impressions. The Data Entry worksheet (see appendix 

C-3 in volume II) has three rows in which ruts are listed (by depth). Determine the 

maximum extent of the rut and record a “1” (present) in the cell for that monitoring point. 

Record a “0” in each of the other two rows. To measure the depth of the rut, you may 

need to determine where the approximate surface of the undisturbed soil is (or was). As 

mentioned previously, you can measure these physical features for area (length multiplied 

by the average width) and enter them into ONSITE to determine areal extent.

Wheel tracks or ruts (impressions in the soil caused by heavy equipment) vary in depth 

and width. On sites that have a high compaction hazard (e.g., fine-textured soils, steep 

slopes), a shallow rut may cause degradation in site quality by altering the flow of 

water and gasses in the soil and/or increasing soil penetration resistance. On sites that 

have a low compaction hazard (e.g., coarse-textured soils), deeper ruts may not cause a 

detrimental change to water and gas flow but may represent displacement of fertile topsoil 

layers. Regardless of texture, however, wheel tracks and ruts can cause water to be routed 

off a site, making it unavailable for plant growth. Within a rut or wheel track could also 

be altered soil structure, increased soil density, puddling, compacted deposits of forest 

floor, fine slash, and woody debris (not readily excavated with a shovel). Placing ruts and 

wheel tracks into a soil disturbance category (disturbance class 1, 2, or 3) is based on their 

depth on the soil surface and their extension into the mineral soil profile. Figure 2 shows 

an example of a rut.
30 Forest Soil Disturbance Monitoring Protocol

Soil Structure. Massive, platy, or puddled soil is recorded on the Data Entry worksheet in 

three separate rows. Determination of a change in structure is by depth and can sometimes 

be linked to the change in compaction level at the same depth. Determine the maximum 

extent of the change in structure and record a “1” (present) in the cell for that monitoring 

point. The other two cells for that monitoring point each will receive a “0” (absent). 

Massive, platy, and puddled soil structure are indicators of a change in soil structure 

and a reduction in pore sizes that will change pore size distribution. Massive soil can be 

naturally occurring or can be caused by management activities. Massive structure means 

structural units are not present and the soil is a coherent mass. Platy structure can also 

be naturally occurring, but coarse-platy structure that has flat, or tabular-like (“dinner 

plate”), units within the profile is usually caused by harvesting equipment. Naturally 

occurring platy structure is not recorded in the field form; only management-induced 

changes in soil structure are recorded. Puddled soils are caused by equipment operating 

when the soil is too wet. Soil is smeared along a wheel track or rut and causes water 

to pond on the surface. The change in soil physical conditions and their depth into the 

mineral soil profile will determine into which soil disturbance class it is placed. 

Surface Organic Matter. A row on the Data Entry worksheet (see appendix C-3) is for 

recording the depth of the forest floor (all surface organic horizons combined). Forest 

floor depth can be used to determine loss of nutrients from the organic layers. If the 

Figure 2.—Example of a rut. Depth of rut will determine in which visual class this monitoring 

point would be placed.
Volume II: Supplementary Methods, Statistics, and Data Collection 31

organic layers are piled and burned, nutrients are lost from the site. Page-Dumroese et 

al. (2000) describe how to use the NRCS soil data to determine approximate nutrient 

amounts and potential losses from organic matter changes due to site activity. Depending 

on site variability, this value can be collected for some (e.g., every 10 points) or all of the 

monitoring points. Measure the forest floor depth with a pocket ruler.

Displacement

Forest Floor. Displacement of the forest floor (all organic horizons above the mineral 

soil) is recorded on the Data Entry worksheet (see appendix C-3). The item on the 

workheet reads “forest floor impacted.” Record either a “0” (forest floor is not impacted) 

or a “1” (forest floor is impacted) in this row for each monitoring point. Large areas of 

displaced forest floor can lead to changes in nutrient cycling or erosion. Changes in the 

distribution and depth of the forest floor will change the soil disturbance severity rating. If 

the area of forest floor displacement is large, the area (length times average width) can be 

measured and entered into the ONSITE portion of the database to determine areal extent.

Mineral Soil. Record removal of the mineral soil is recorded under “Topsoil Displacement” in the Data Entry worksheet (see appendix C-3). Record either a “0” (displacement 

is absent) or a “1” (displacement is present) in this row for each monitoring point. Mineral 

soil displacement and gouging can result in degradation of site quality by exposing unfavorable subsoil material (e.g., denser, lower in nutrients, less organic matter, calcareous), 

altering slope hydrology and causing excessive erosion and, therefore, a loss of nutrients. 

Displacement that has removed most of the top mineral soil and exposed the subsoil is 

considered soil disturbance class 3 (fig. 3). See figure 4 for a schematic of several impacts 

in one location (rutting, displacement, and forest floor impacted). The effects of mineral 

Figure 3.—Example of combined rutting (foreground) and surface soil displacement (background).
32 Forest Soil Disturbance Monitoring Protocol

soil displacement on long-term productivity are governed by slope gradient, slope complexity, and subsoil conditions. 

Changes in the soil disturbance categories are based on mixing of topsoil with the subsoil, 

topsoil removal, or evidence of gouging and piling. This attribute is the only one tied 

to an areal extent in some Forest Service regional soil quality standards and guidelines. 

Documentation should be made of the areal extent used by individuals before monitoring 

and should also be listed in the comment field. Because the electronic field form is used 

to calculate ongoing sample size using “0s” and “1s,” areal extent size must be listed elsewhere. For example, if the displaced area is >1.5 m (5 ft) in diameter, then it is counted as 

“1” (present). Any area smaller than the selected areal extent is counted as “0” (absent). 

In addition, if areas of mineral topsoil displacement are extraordinarily large, they can be 

measured for area (length times average width) and entered into the ONSITE calculator.

Point Attributes

After recording information about forest floor impacted, use the section on the Data 

Entry worksheet (see appendix C-3) that asks for information about live plants, invasive 

species, fine woody material, coarse woody material, bare soil, and rock. These attributes 

are meant to help describe site conditions that may indicate a change in site sustainability 

or erosion potential. These attributes are not automatically included in the sample size 

calculation on the Variable Selection worksheet (see appendix C-2). If these attributes are 

important for particular sites, however, they may be included in the sample size calculation.

Figure 4.—Schematic of surface soil displacement, rut, and forest floor impacted (from Napper 

et al. N.d.).
Volume II: Supplementary Methods, Statistics, and Data Collection 33

Erosion 

Record erosion on the Data Entry worksheet (see appendix C-3) under “erosion.” Record 

either a “0” (absent) or a “1” (present) in this row for each sample point. Soil erosion is 

the movement of soil by water and wind. Accelerated erosion (erosion caused by human 

activities that is more than the historic erosion rate) causes both onsite (soil loss, nutrient 

loss, lower productivity, and shallower mineral soil) and offsite (reduced stream water 

quality, increased sedimentation, and loss of habitat) effects. 

Erosion noted in the FSDMP is for surface soils within an activity area. It is not designed 

for roads, ditches, or places where the subsoil is exposed. The degree and extent (slight, 

moderate, or severe) of erosion will place this attribute into different soil disturbance classes. 

Prescribed Fire and Pile Burning

Prescribed fire severity is recorded on the Data Entry worksheet (see appendix C-3). The 

worksheet has three rows in which fire severity is listed (light, moderate, and severe). 

These levels of severity have been defined by the Burned-Area Emergency Rehabilitation 

Handbook (USDA Forest Service 1976). Determine the fire severity of the monitoring 

point and record a “1” (present) in the cell for that monitoring point. Record a “0” in the 

other two cells for that monitoring point.

Broadcast Burning. Broadcast burns across the activity area will probably create a 

mosaic of site conditions. Low-severity burns will probably not alter soil processes for 

an extensive period of time. Hotter burns may affect both the forest floor and mineral soil 

material. As burn intensity increases, the soil disturbance class (1, 2, or 3) also increases. 

As noted previously, the burn severity levels have already been defined. If burning is light 

(depth of char in the mineral soil <1 cm), then assign soil disturbance class 1. If burning is 

moderate (depth of char increases up to 5 cm), then assign disturbance class 2. Finally, if 

burning is severe (depth of char >5 cm), then assign disturbance class 3. 

Pile Burning. Piles of waste logging materials, understory brush, small trees, or tree tops 

(slash) that remain after harvest activities are often burned within the activity area or on 

landings and skid trails. It may be difficult to describe conditions under the burned area if 

substantial slash remains, but it is critical to assess the size (width times length or diameter) of the area. ONSITE can be used to help calculate the size of these features. Because 

sample points land on different piles, assess them independently for severity. Assess the 

soil under the burn piles similarly to broadcast burning severity.
34 Forest Soil Disturbance Monitoring Protocol

Soil disturbance classes are identified using visual surface characteristics and are 

recorded for each point in the survey. The disturbances classes are defined in the above 

sections and table 2. Table 3 provides a listing of the soil visual indicators and how they 

may be associated with management activities. Data collected at each monitoring point 

provide a representative sample of the activity area. The percentage of the activity area in 

each soil disturbance class is calculated within the electronic spreadsheet (see the Results 

worksheet, appendix C-4). Reliability is estimated from the variance among estimated 

point proportions of each condition class. Some monitoring points may have a variety of 

soil disturbances. These overlapping indicators will have to be evaluated by the observer 

so that the soil disturbance class best represents the point sample (see figure 4). 

Assigning a Disturbance Class
Volume II: Supplementary Methods, Statistics, and Data Collection 35

A picture guide of the visual disturbance classes (Napper et al. N.d.) outlined in table 2 

and a standardized training curriculum will be available by the end of 2009. Both of these 

efforts, plus the standardization of protocols and definitions, will help ensure that highquality data are being collected consistently. In addition, regional soil program managers 

and forest soil scientists should conduct periodic local training for new employees using 

the FSDMP. Work is continuing on the national electronic database. 

Quality Assurance and Quality Control
36 Forest Soil Disturbance Monitoring Protocol

activity area. A harvest unit, excluding system roads, as well as landings and temporary 

roads, outside the harvest unit boundary. An activity area may also be a prescribed burn 

unit or any area delineated on the ground for a specific treatment. 

areal extent. The measured area (length times width or diameter) affected by any activity.

biological indicators of soil quality. Measures of living organisms or their activity used 

as indicators of soil quality. Measuring soil organisms can be done in three general ways: 

1. Counting soil organisms or measuring microbial biomass. 

2. Measuring biologic activity (e.g., soil basal respiration, cotton strip assay, or 

potentially mineralizable nitrogen). 

3. measuring diversity, such as diversity of functions (e.g., BIOLOG plates) or 

diversity of chemical structure (e.g., cell components, fatty acids, or DNA). 

chemical indicators of soil quality. Indicators that include tests of organic matter, pH, 

electrical conductivity, heavy metals, cation exchange capacity, and other parameters. 

dynamic soil quality. An aspect of soil quality relating to soil properties that change as a 

result of soil use and management or over the human time scale. 

erosion. The detachment and movement of soil or rock by water, wind, ice, or gravity. 

forest floor. All organic soil horizons consisting of dead plant material on the surface of 

the mineral soil surface.

inherent soil quality. An aspect of soil quality relating to a soil’s natural composition 

and properties as influenced by the factors and processes of soil formation in the absence 

of human effects. 

physical indicators of soil disturbance. Characteristics that vary with management and 

that include bulk density, aggregate stability, infiltration, hydraulic conductivity, and 

penetration resistance. 

platy soil structure. The arrangement of soil particles into aggregates that is flat horizontally. Platy structure can be natural or caused by trafficking.

puddling. The destruction of soil structure and the associated loss of macro porosity that 

results from working on a soil that is wet. 

Glossary
Volume II: Supplementary Methods, Statistics, and Data Collection 37

soil function. Any service, role, or task that soil performs, especially the following: 

1. Sustaining biological activity, diversity, and productivity. 

2. Regulating and partitioning water and solute flow (hydrologic function). 

3. Filtering, buffering, degrading, and detoxifying potential pollutants.

4. Storing and cycling nutrients.

5. Providing support for buildings and other structures (trees) and protecting 

archaeological treasures (cultural features). 

soil quality. The capacity of a specific kind of soil to function, within natural or managed 

ecosystem boundaries, to sustain plant and animal productivity, maintain or enhance 

water and air quality, and support human health and habitation and ecosystem health. Two 

aspects of the definition are dynamic soil quality and inherent soil quality. 

soil quality indicator. A quantitative or qualitative measure used to estimate soil 

functional capacity. Indicators should be adequately sensitive to change, accurately reflect 

the processes or biophysical mechanisms relevant to the function of interest, and be cost 

effective and relatively easy and practical to measure. Soil quality indicators are often 

categorized into biological, chemical, and physical indicators. 

soil quality monitoring. The act of tracking trends in quantitative indicators or the 

functional capacity of the soil to determine the success of, or changes associated with, 

management practices (land uses or disturbances) or the need for additional management 

changes. Monitoring involves the orderly collection, analysis, and interpretation of data 

from the same locations over time. 
38 Forest Soil Disturbance Monitoring Protocol

Block, R.; Van Rees, K.C.J.; Pennock, D.J. 2002. Quantifying harvesting impacts using 

soil compaction and disturbance regimes at a landscape scale. Soil Science Society of 

America Journal. 66: 1669–1676.

Burger, J.A.; Kelting, D.L. 1998. Soil quality monitoring for assessing sustainable forest 

management. In: Adams, M.B.; Ramakrishna, K.; Davidson, E., eds. The contribution of 

soil science to the development and implementation of criteria and indicators of sustainable forest management. SSSA Spec. Publ. 53. Madison, WI: Soil Science Society of 

America: 17–53.

Burger, J.A.; Kelting, D.L. 1999. Using soil quality indicators to assess forest stand 

management. Forest Ecology and Management. 122: 155–166.

Busse, M.D.; Beattie, S.E.; Powers, R.F., et al. 2006. Microbial community responses 

in forest mineral soil to compaction, organic matter removal, and vegetation control. 

Canadian Journal of Forest Research. 36: 577–588.

Clayton, J.L.; Kellogg, G.; Forrester, N. 1987. Soil disturbance-tree growth relations in 

central Idaho clearcuts. Research Note INT-372. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Research Station. 6 p.

Cochran, P.H.; Brock, T. 1985. Soil compaction and initial height growth of planted 

ponderosa pine. Research Note PNW-434. Portland, OR: U.S. Department of Agriculture, 

Forest Service, Pacific Northwest Forest and Range Experiment Station. 10 p.

Craigg, T.L.; Howes, S.W. 2007. Assessing quality in volcanic ash soils. In: PageDumroese, D.S.; Miller, R.E.; Mital, J., et al., tech. eds. Volcanic-ash-derived forest soils 

of the Inland Northwest: properties and implications for management and restoration. 

Proceedings, Volcanic-Ash-Derived Forest Soils of the Inland Northwest: Properties 

and Implications for Management and Restoration. RMRS-P-44. Fort Collins, CO: U.S. 

Department of Agriculture, Forest Service, Rocky Mountain Research Station: 47–67.

Curran, M.; Maynard, D.; Heninger, R., et al. 2007. Elements and rationale for a common 

approach to assess and report soil disturbance. The Forestry Chronicle. 83: 852–866.

Curran, M.P., Miller, R.E.; Howes, S.W., et al. 2005. Progress toward more uniform 

assessment and reporting of soil disturbance for operations, research, and sustainability 

protocols. Forest Ecology and Management. 220: 7–30.

Literature Cited 
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Doran, J.W.; Parkin, T.B. 1994. Defining and assessing soil quality. In: Doran, J.W.; 

Coleman, D.C.; Bezdicek, D.F., et al., eds. Defining soil quality for a sustainable environment. SSSA Spec. Pub. 35. Madison, WI: Soil Science Society of America: 3–11.

Fleming, R.L.; Powers, R.F.; Foster, N.W., et al. 2006. Effects of organic matter removal, 

soil compaction, and vegetation control on 5-year seedling performance: a regional 

comparison of Long-Term Soil Productivity sites. Canadian Journal of Forest Research. 

36: 5429–5450.

Froehlich, H.A. 1976. The influence of different thinning systems on damage to soil and 

trees. Proceedings, XVI IUFRO World Congress Division IV. Oslo, Norway: International Union of Forest Research Organizations: 333–334.

Gomez, A.; Powers, R.F.; Singer, M.J., et al. 2002. Soil compaction effects on growth of 

young ponderosa pine following litter removal in California’s Sierra Nevada. Soil Science 

Society of America Journal. 66: 1334–1343.

Heninger, R.; Scott, W.; Dobkowski, A., et al. 2002. Soil disturbance and 10-year growth 

response of coast Douglas-fir on nontilled and tilled skid trails in the Oregon Cascades. 

Canadian Journal of Forest Research. 32: 233–246.

Herrick, J.E.; VanZee, J.W.; Havstad, K.M., et al. 2005. Monitoring manual for grassland, 

shrubland and savanna ecosystems. Vol. I: Quick start. Las Cruces, NM: U.S. Department 

of Agriculture, Agricultural Research Service Jornada Experimental Range. 36 p.

Howes, S.; Hazard, J.; Geist, J.M. 1983. Guidelines for sampling some physical conditions of surface soils. R6-RWM-146-1983. Portland, OR: U.S. Department of Agriculture, 

Forest Service, Pacific Northwest Region. 34 p.

Howes, S.W. 2006. Soil disturbance monitoring in the USDA Forest Service, Pacific 

Northwest Region. Proceedings, Monitoring Science and Technology Symposium: 

Unifying Knowledge for Sustainability in the Western Hemisphere. RMRS-P-42CD. Fort 

Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research 

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Laing, L.E.; Howes, S.W. 1988. Detrimental soil compaction resulting from a feller 

buncher and rubber-tired skidder timber harvest operation: a case study. In: Lousier, J.D.; 

Still, G.W., eds. Degradation of forested lands: forest soils at risk. Proceedings, 10th B.C. 

Soil Science Workshop. 191–195.
40 Forest Soil Disturbance Monitoring Protocol

Larson, W.E.; Pierce, F.J. 1994. The dynamics of soil quality as a measure of sustainable 

management. In: Doran, J.W.; Coleman, D.C.; Bezdicek, D.F., et al., eds. Defining soil 

quality for a sustainable environment. SSSA Spec. Pub. 35. Madison, WI: Soil Science 

Society of America: 37–51.

McNab, W.H.; Cleland, D.T.; Freeouf, J.A., et al., comps. 2007. Description of ecological 

subregions: sections of the conterminous United States [CD-ROM]. Gen. Tech. Rep. 

WO-76B. Washington, DC: U.S. Department of Agriculture, Forest Service. 80 p.

Morris, L.A.; Miller, R.E. 1994. Evidence for long-term productivity change as provided 

by field trials. In: Dyck, W.J., ed. Impacts of forest harvesting on long-term site productivity. London, United Kingdom: Chapman & Hall 41–80.

Napper, C.; Howes, S.; Page-Dumroese, D. [N.d.]. Soil disturbance field guide. Manuscript in preparation. 0820 1815-SDTDC. San Dimas, CA: San Dimas Technology 

Center.

Page-Dumroese, D.; Jurgensen, M.; Abbott, A., et al. 2006. Monitoring changes in soil 

quality from postfire logging in the Inland Northwest. In: Andrews, P.L.; Butler, B.W., 

comps. Proceedings, Fuels Management: How To Measure Success. RM-P-41. Ft. Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research 

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guidelines for forest sustainability in northwestern North America. Forest Ecology and 

Management. 138: 445–462.

Page-Dumroese, D.S.; Jurgensen, M.F.; Tiarks, A.E., et al. 2006. Soil physical property 

changes at North American Long-Term Soil Productivity study sites: 1 and 5 years after 

compaction. Canadian Journal of Forest Research. 36: 551–564.

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American forests: problems and prospects. In: Gessel, S.P.; Lacate, D.S.; Weetman, G.F., 

et al., eds. Sustained productivity of forest soils. Proceedings, 7th North American Forest 

Soils Conference. Vancouver, British Columbia: University British Columbia, Faculty of 

Forestry: 49–79.

Powers, R.F.; Scott, D.A.; Sanchez, F.G., et al. 2005. The North American long-term soil 

productivity experiment: findings from the first decade of research. Forest Ecology and 

Management. 220: 17–30.
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Powers, R.F.; Tiarks, A.E.; Boyle, J.R. 1998. Assessing soil quality: practical standards 

for sustainable forest productivity in the United States. In: Adams, M.B.; Ramakrishna, K.; 

Davidson, E., eds. The contribution of soil science to the development and implementation of criteria and indicators of sustainable forest management. SSSA Spec. Publ. 53. 

Madison, WI: Soil Science Society of America: 53–80.

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matter removal and soil compaction on loblolly pine growth over 10 years. Forest Ecology and Management. 227: 145–154.

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and sampling soils. Lincoln, NE: U.S. Department of Agriculture, Natural Resources 

Conservation Service, National Soil Survey Center.

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of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station: 

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42 Forest Soil Disturbance Monitoring Protocol

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Conservation. 50: 226–228.
Volume II: Supplementary Methods, Statistics, and Data Collection 43

For each option listed below, a minimum of 30 monitoring points is required to calculate 

the remainder of the sample size. 

Option 1. Randomly Oriented Transects

Appendix A. Options for Monitoring Point Layout

Established transects. Pre-established grid (randomly oriented) with transects oriented along 

random azimuths. Transects are of standard length, usually 100 ft.

In this option, transects are laid out randomly on a site map before going to the field. 

Monitoring points can be collected along these randomly established transects to collect 

the minimum number of points needed. At each intersection, a 30-m (~100-ft) transect is 

established. The attributes are then noted at monitoring points located along each transect. 

Option 2. Systematic Grid Points

In this option, the protocol calls for establishing a systematic grid of monitoring points 

arrayed on a map or aerial photograph of the activity area to be monitored. The entire 

grid is randomly located and oriented, and the distance between monitoring points is 

constructed to provide a sample size that meets precision requirements or cost limitations 

specified in the objectives for monitoring. Each grid intersection locates a monitoring point 

that radiates in a random chosen direction and distance from the grid point (Howes 2006).
44 Forest Soil Disturbance Monitoring Protocol

Option 3. A Random Transect

In this option, the protocol calls for randomly locating a start point and traversing a 

transect that covers the entire unit so that the first 30 monitoring points (the minimum 

required) are spaced to provide an adequate assessment of the site. The entire transect is 

randomly located and oriented, and the distance between monitoring points is constructed 

to provide a sample size that meets precision requirements or cost limitations specified 

in the objectives for monitoring. Turning points are usually located within the activity 

area so that the last monitoring point before a turn is not within an area of influence of the 

surrounding stand (usually the height of the tallest trees). Additional transects at random 

directions are often needed to reach the appropriate sample size. If the transect begins to 

follow a skid road, either offset from the skid road or start a new random transect. Record 

offset or new direction.
Volume II: Supplementary Methods, Statistics, and Data Collection 45

Appendix B. Statistical Background of the Forest 

Soil Disturbance Monitoring Protocol

The goal of the data collection process using the Forest Soil Disturbance Monitoring 

Protocol (FSDMP) is to obtain a representative estimate of the amount and types of 

management-induced disturbance within a particular activity area. Although there is a 

“true” proportion of any area that is disturbed, the only way to determine that true proportion 

would be to measure every possible point within the entire activity area. Because monitoring every point is impossible, given time and budget constraints, a sample of monitoring 

points must be taken. When the sample is chosen randomly (every possible monitoring 

point within the area has the same probability of being chosen) and “large enough,” it can 

be considered representative of the activity area as a whole.

A large enough sample is determined by first specifying the confidence level that is 

acceptable for the monitoring estimate. As the level of confidence increases, so does the 

number of monitoring points necessary to estimate the disturbance (assuming that the 

variability stays constant). The confidence level can be chosen by the user in consultation 

with a line officer if necessary. The confidence level is specified within either the SoLo 

Info or Data Entry worksheets (see appendixes C-1 and C-3, respectively) or by choosing 

the appropriate column on the sample size tables (see appendixes D-2 and D-3), and then 

finding the associated sample size for a given proportion of disturbed monitoring points. 

At this time, available confidence levels within the electronic worksheets range from 70 to 

95 percent. The margin of error around each estimate is either ± 5 or ±10 percent (with an 

overall confidence width of ±10 or ±20), meaning that, after the proportion of disturbance 

for a particular variable is estimated for the activity area, the interval calculated by taking 

the sample proportion ±5 percent (or ±10 percent) will contain the true proportion with 

the chosen level of confidence. The sample size tables also contain information to calculate sample size with confidence levels from 70 to 95 percent. Sample size information 

with the margin of error at ±5 percent is found in appendix D-2. Sample size information 

with the margin of error at ±10 percent sample size calculations is in appendix D-3.

The sample size required to estimate the proportion of disturbance is first calculated 

individually for each indicator variable. The overall sample size that should be used for 

monitoring is the largest of the individual sample sizes to ensure that the margin of error 

is within acceptable limits for every indicator variable. Sample sizes are not dependent 

on the size of the activity area; they are dependent only on the level of confidence and 

the amount of variability estimated from the sample points within an activity area. The 

procedure outlined here is a point sample and, within any size activity area, the number of 

potential points to sample is infinite.
46 Forest Soil Disturbance Monitoring Protocol

All the indicator variables that contribute to the overall sample size calculation are binomial variables, meaning they can take on only one of two values: either the characteristic 

is “1” (present) or “0” (absent.) When the sample size is at least 30, the normal approximation to the binomial distribution can be used (Triola 2001]). Using binary variables as 

the basis for the sample size determination has several advantages (Sheaffer et al. 1996). 

The maximum possible variability for any site is a fixed number that is reached when 

50 percent of the monitoring points have the characteristic and 50 percent do not. Using 

binary variables allows for variability to be estimated and sample size calculated in the 

field on a single sampling trip with a simple set of calculations. The FSDMP uses a minimum of 30 monitoring points from the initial transect as the “pilot” data for any given 

area and thus ensures that the sample size necessary for each area is based on accurate 

variability estimates within that area. 

The required sample size for each indicator variable is calculated according to the following formula:

Variables within this formula are as follows:

• is the standard normal percentile yielding the chosen confidence level. The 

user must specify the desired confidence level within the electronic data entry 

spreadsheet or choose the appropriate column from the sample size tables (see 

appendixes D-2 and D-3). 

pˆ • is the observed proportion of monitoring points that have disturbance and are 

marked “present” by recording a “1.” This proportion is computed by adding the 

total number of “1s” and dividing by the total number of monitoring points. The 

electronic spreadsheet will perform this calculation automatically; however, those 

using a paper copy of the electronic form (see appendix D-1) must calculate this 

proportion in the field.

qˆ • is the observed proportion of monitoring points that do not have disturbance and 

are marked “absent” by recording a “0.” This proportion is computed by adding the 

total number of “0s” and dividing by the total number of monitoring points or by 

subtracting pˆ (as found above) from 1 since pˆ + qˆ = 1.

• w is the 1/2-width of the confidence interval. At this time, the sample sizes are 

calculated based on a confidence-interval width of 10 percent (or 20 percent), 

which will result in the estimates with a plus or minus 5 percent (or 10 percent) 

margin of error.
Volume II: Supplementary Methods, Statistics, and Data Collection 47

For example, with an 80-percent confidence level, at the calculated sample size, the 

confidence interval given by the range pˆ ± 5% will have “captured” the true proportion of 

disturbed points in the activity area 80 percent of the time. 

The minimum number of monitoring points is 30. This minimum number is required 

when using the above formula to calculate sample size and confidence intervals. If 

fewer than 30 monitoring points are taken, the sample sizes and confidence intervals 

calculated within the spreadsheet will be incorrect. The consequence of using more than 

30 samples but fewer than the number recommended by the sample size calculator within 

the electronic spreadsheet or on a paper copy of the electronic form (see appendix D-1) is 

that the confidence interval may be wider, as indicated by the “Lower Bound” and “Upper 

Bound” values on the spreadsheet (see Results worksheet, appendix C-4).

The confidence intervals calculated on the electronic spreadsheet are the actual confidence 

intervals from the initial monitoring data along the sampling transect and may be used as 

summary data for reporting. For those using the paper copy of the electronic form (see 

appendix D-1), we suggest entering the data into the electronic spreadsheet to obtain the 

intervals with no manual calculation. The formulas for the lower and upper bounds of the 

confidence intervals are as follows:

Lower Bound = 

Upper Bound = 

where the variables are previously defined for the sample size formula. The values for 

are shown here:

Confidence Level

70% 1.04

75% 1.15

80% 1.282

85% 1.44

90% 1.645

95% 1.96

In the electronic spreadsheet on the tab labeled Results (see appendix C-4), the estimated 

proportion of disturbance for the area is shown along with the lower and upper bounds 

of the confidence interval for each indicator variable. These values are provided for 

convenience in final reporting. The correct interpretation of the confidence intervals 

can be illustrated with the following example: if an activity area yields a pˆ for the 

indicator variable “rutting <5cm” of 0.1545 and the required sample size of 109 (from an 
48 Forest Soil Disturbance Monitoring Protocol

85-percent confidence level) was met by taking 110 monitoring points, the lower bound 

is 0.104916 and the upper bound is 0.204175. This example shows that, with 85-percent 

confidence, the interval (0.1, 0.2) has captured the true proportion of rutting less than 5 cm 

within this particular activity area. It should be noted that intervals calculated for low 

levels of disturbance (less than 5 percent) are truncated to have a lower bound of zero 

because negative values are impossible.

Summary levels of disturbance classes are also provided within the electronic Data Entry

spreadsheet (see appendix C-3). Because this variable is ordinal (meaning that levels of 

this variable are ordered categories), confidence intervals may not be calculated.
Volume II: Supplementary Methods, Statistics, and Data Collection 49

Appendix C. Examples of Worksheets Contained 

in the Forest Soil Disturbance Monitoring 

Protocol Spreadsheet

Appendix C-1. Example Worksheet for Collecting Soil Disturbance 

Monitoring Data (SoLo Info)

The first tab of the electronic spreadsheet is a worksheet labeled SoLo Info (shown below). 

Use this worksheet to describe the site attributes. Additional details of the information 

requested in this worksheet are described in appendix G. In the Indicator section of this 

worksheet, #DIV/0! will be automatically filled in when the Data Entry (see appendix C-3) 

worksheet is completed.

SoLo Soil Quality Monitoring Report:

Site Identification:

Project ID:

Unit ID:

Subunit ID:

Project Type:

Other (Comment):

Location Information

Region:

Forest:

District:

USGS Quad(s):

Section(s):

Township:

Range:

Meridian:

Latitude: 0.000000

Longitude: 0.000000

Datum: 0

UTM Easting: 0

UTM Northing: 0

UTM Zone: 0

GIS Coverage:

Polygon ID:

Site Characteristics:

Slope (%):

Aspect (degrees or direction):

Elevation (feet? meters?):

Area (acres? hectares?):

Ecological Subsection:

Landform/Topography:

Habitat Type:

Watershed Name:

Watershed HUC:

Watershed Condition Class:

Landtype Association:

Parent Material:

Soil Classification:

Soil Survey:

Comments:
50 Forest Soil Disturbance Monitoring Protocol

Site History:

Wildfire (season & year):

Grazing (span of years):

Harvest (season & year):

Harvest System:

Site Prep (including Rx fire):

Planted (year):

Thinned (year):

Recreational Use:

Roading (miles/kilometers):

Deroading:

Other Reclamation:

Other (Comment):

Current Activity:

Prescription (treatment):

Method/System:

Monitoring Type:

Confidence Level Selected: 95

Confidence Interval Selected: 10

Number of Points in Survey: 0

Indicator: Proportion Positive

Forest Floor Impacted: #DIV/0!

Displacement: #DIV/0!

Erosion: #DIV/0!

Rutting: #DIV/0!

Burning: #DIV/0!

Compaction: #DIV/0!

Platy/Massive/Puddled: #DIV/0!

Other (Comment):

Administrative Information:

Observer:

Observer Title:

Observer E-mail:

Date Monitored: 1/0/1900

Date Approved:

Approver:

Approver Title:

Approver E-mail:

Date Reported:

NEPA Document:

Date NEPA Completed:

GIS = Geographic Information System. HUC = Hydrologic Unit 

Code. NEPA = National Environmental Policy Act. UTM = Universal 

Transverse Mercator.
Volume II: Supplementary Methods, Statistics, and Data Collection 51

Appendix C-2. Example Worksheet for Collecting Soil Disturbance 

Monitoring Results (Variable Selection)

The second tab of the electronic spreadsheet for data collection is the worksheet labeled 

Variable Selection and is shown below. Changing the entries for any particular variable 

from 1 to 0 results in those variables being excluded in the sample size calculation; 

however, summary statistics and confidence intervals will still be calculated.

Select the variables to be included in the sample size calculation

Enter 1 to include	

Enter 0 to exclude	

Forest Floor Impacted?	 1

Live Plant?	 0

Invasive Plant?	 0

Fine Woody? <7 cm	 0

Coarse Woody? >7cm	 0

Bare Soil?	 0

Rock?	 0

Topsoil Displacement?	 1

Erosion? Comment!	 1

Rutting? <5cm	 1

Rutting? 5-10cm	 1

Rutting? >10cm	 1

Burning Light	 1

Burning Moderate	 1

Burning Severe	 1

Compaction? 0-10 cm	 1

Compaction? > 10-30 cm	 1

Compaction? >30 cm	 1

Platy/Massive/Puddled Structure 0-10 cm	 1

Platy/Massive/Puddled Structure >10-30 cm	 1

Platy/Massive/Puddled Structure >30 cm	 1
52 Forest Soil Disturbance Monitoring Protocol

51

Appendix C-3. Example Worksheet for Collecting Soil Disturbance Monitoring Results (Data Entry)The third tab of the electronic spreadsheet for data collection is a worksheet labeled Data Entry. Record either “0” (absent) or “1” (present) in each cell of the spreadsheet except for forest floor depth. Forest floor depth is recorded in centimeters. NOTE: This spreadsheet example contains only 23 data points.

Project ID: 0 Unit ID: 0 Observer: 0Date:

Monitoring Type: 0 Point Spacing (m):

Direction:Sample point 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23f. floor depth (cm):Forest floor Impacted?Live Plant?Invasive Plant?Fine Woody? <7 cmCoarse Woody? >7cmBare Soil?Rock?Topsoil displacement?Erosion?, comment!Rutting? <5cmRutting? 5-10cmRutting? >10cmBurning lightBurning moderateBurning severeCompaction? 0-10 cm

Appendix C-3. Example Worksheet for Collecting Soil Disturbance Monitoring Results (Data Entry)The third tab of the electronic spreadsheet for data collection is a worksheet labeled Data Entry. Record either “0” (absent) or “1” (present) in each cell of the spreadsheet except for forest floor depth. Forest floor depth is recorded in centimeters.NOTE: This spreadsheet example contains only 23 data points. 
Volume II: Supplementary Methods, Statistics, and Data Collection 53

52

Compaction? 10-30 cmCompaction? >30cmPlaty/Massive/Puddled structure 0-10 cmPlaty/Massive/Puddled structure 10-30 cmPlaty/Massive/Puddled structure >30 cm

N Needed (round UP)

#DIV/0!

Estimated Soil Disturbance ClassDetrimental? Enter 1 if Yes, 0 if NoComments

Rutting? >10cmBurning lightBurning moderateBurning severeCompaction? 0-10 cm
54 Forest Soil Disturbance Monitoring Protocol

Appendix C-4. Example Worksheet for Collecting Soil Disturbance 

Monitoring Results (Results)

The fourth tab of the electronic spreadsheet for data collection is a worksheet labeled 

Results. Note that as columns in the Data Entry tab are filled out, the “#DIV/0!” will be 

replaced with the calculated results.
Volume II: Supplementary Methods, Statistics, and Data Collection 55 Appendix D. Paper Field Form and Tables for Determining Sample Size Appendix D-1. Example of Paper Field Form Note: This form contains only 30 sample points.
56 Forest Soil Disturbance Monitoring Protocol
Volume II: Supplementary Methods, Statistics, and Data Collection 57

70% Confidence 75% Confidence 80% Confidence 85% Confidence 90% Confidence 95% Confidence

Percent 

Present 

 N 

Required

Percent 

Present 

 N 

Required

Percent 

Present 

 N 

Required

Percent 

Present 

 N 

Required

Percent 

Present 

 N 

Required

Percent 

Present 

 N 

Required

1% 5 1% 6 1% 7 1% 9 1% 11 1% 16

2% 9 2% 11 2% 13 2% 17 2% 22 2% 31

3% 13 3% 16 3% 20 3% 25 3% 32 3% 45

4% 17 4% 21 4% 26 4% 32 4% 42 4% 60

5% 21 5% 26 5% 32 5% 40 5% 52 5% 73

6% 25 6% 30 6% 37 6% 47 6% 62 6% 87

7% 29 7% 35 7% 43 7% 54 7% 71 7% 101

8% 32 8% 39 8% 49 8% 62 8% 80 8% 114

9% 36 9% 44 9% 54 9% 68 9% 89 9% 126

10% 39 10% 48 10% 59 10% 75 10% 98 10% 139

11% 43 11% 52 11% 65 11% 82 11% 106 11% 151

12% 46 12% 56 12% 70 12% 88 12% 115 12% 163

13% 49 13% 60 13% 75 13% 94 13% 123 13% 174

14% 53 14% 64 14% 79 14% 100 14% 131 14% 186

15% 56 15% 68 15% 84 15% 106 15% 139 15% 196

16% 59 16% 72 16% 89 16% 112 16% 146 16% 207

17% 62 17% 75 17% 93 17% 118 17% 153 17% 217

18% 64 18% 79 18% 97 18% 123 18% 160 18% 227

19% 67 19% 82 19% 101 19% 128 19% 167 19% 237

20% 70 20% 85 20% 105 20% 133 20% 174 20% 246

21% 72 21% 88 21% 109 21% 138 21% 180 21% 255

22% 75 22% 91 22% 113 22% 143 22% 186 22% 264

23% 77 23% 94 23% 117 23% 147 23% 192 23% 273

24% 79 24% 97 24% 120 24% 152 24% 198 24% 281

25% 82 25% 100 25% 123 25% 156 25% 203 25% 289

26% 84 26% 102 26% 127 26% 160 26% 209 26% 296

27% 86 27% 105 27% 130 27% 164 27% 214 27% 303

28% 88 28% 107 28% 133 28% 168 28% 219 28% 310

29% 90 29% 109 29% 135 29% 171 29% 223 29% 317

30% 91 30% 112 30% 138 30% 175 30% 228 30% 323

31% 93 31% 114 31% 141 31% 178 31% 232 31% 329

32% 95 32% 116 32% 143 32% 181 32% 236 32% 335

33% 96 33% 117 33% 145 33% 184 33% 240 33% 340

34% 98 34% 119 34% 148 34% 187 34% 243 34% 345

35% 99 35% 121 35% 150 35% 189 35% 247 35% 350

36% 100 36% 122 36% 151 36% 192 36% 250 36% 355

37% 101 37% 124 37% 153 37% 194 37% 253 37% 359

38% 102 38% 125 38% 155 38% 196 38% 256 38% 363

39% 103 39% 126 39% 156 39% 198 39% 258 39% 366

40% 104 40% 127 40% 158 40% 200 40% 260 40% 369

41% 105 41% 128 41% 159 41% 201 41% 262 41% 372

42% 106 42% 129 42% 160 42% 203 42% 264 42% 375

43% 107 43% 130 43% 161 43% 204 43% 266 43% 377

44% 107 44% 131 44% 162 44% 205 44% 267 44% 379

45% 108 45% 131 45% 163 45% 206 45% 268 45% 381

46% 108 46% 132 46% 163 46% 207 46% 269 46% 382

47% 108 47% 132 47% 164 47% 207 47% 270 47% 383

48% 108 48% 133 48% 164 48% 208 48% 271 48% 384

49% 109 49% 133 49% 164 49% 208 49% 271 49% 385

50% 109 50% 133 50% 164 50% 208 50% 271 50% 385

N = number.

Notes: These sample sizes are based on the Normal Approximation to the Binomial Distribution; a minimum sample size of 30 is required for 

this approximation to be valid. Shaded areas represent sample sizes of less than 30.

Appendix D-2. Determining Sample Size With a Margin of Error at ± 5 Percent
58 Forest Soil Disturbance Monitoring Protocol

70% Confidence 75% Confidence 80% Confidence 85% Confidence 90% Confidence 95% Confidence

Percent

Present 

 N 

Required

Percent

Present 

 N 

Required

Percent

Present 

 N 

Required

Percent

Present 

 N 

Required

Percent

Present 

 N 

Required

Percent

Present 

 N 

Required

1% 2 1% 2 1% 2 1% 3 1% 3 1% 4

2% 3 2% 3 2% 4 2% 5 2% 6 2% 8

3% 4 3% 4 3% 5 3% 7 3% 8 3% 12

4% 5 4% 6 4% 7 4% 8 4% 11 4% 15

5% 6 5% 7 5% 8 5% 10 5% 13 5% 19

6% 7 6% 8 6% 10 6% 12 6% 16 6% 22

7% 8 7% 9 7% 11 7% 14 7% 18 7% 26

8% 8 8% 10 8% 13 8% 16 8% 20 8% 29

9% 9 9% 11 9% 14 9% 17 9% 23 9% 32

10% 10 10% 12 10% 15 10% 19 10% 25 10% 35

11% 11 11% 13 11% 17 11% 21 11% 27 11% 38

12% 12 12% 14 12% 18 12% 22 12% 29 12% 41

13% 13 13% 15 13% 19 13% 24 13% 31 13% 44

14% 14 14% 16 14% 20 14% 25 14% 33 14% 47

15% 14 15% 17 15% 21 15% 27 15% 35 15% 49

16% 15 16% 18 16% 23 16% 28 16% 37 16% 52

17% 16 17% 19 17% 24 17% 30 17% 39 17% 55

18% 16 18% 20 18% 25 18% 31 18% 40 18% 57

19% 17 19% 21 19% 26 19% 32 19% 42 19% 60

20% 18 20% 22 20% 27 20% 34 20% 44 20% 62

21% 18 21% 22 21% 28 21% 35 21% 45 21% 64

22% 19 22% 23 22% 29 22% 36 22% 47 22% 66

23% 20 23% 24 23% 30 23% 37 23% 48 23% 69

24% 20 24% 25 24% 30 24% 38 24% 50 24% 71

25% 21 25% 25 25% 31 25% 39 25% 51 25% 73

26% 21 26% 26 26% 32 26% 40 26% 53 26% 74

27% 22 27% 27 27% 33 27% 41 27% 54 27% 76

28% 22 28% 27 28% 34 28% 42 28% 55 28% 78

29% 23 29% 28 29% 34 29% 43 29% 56 29% 80

30% 23 30% 28 30% 35 30% 44 30% 57 30% 81

31% 24 31% 29 31% 36 31% 45 31% 58 31% 83

32% 24 32% 29 32% 36 32% 46 32% 59 32% 84

33% 24 33% 30 33% 37 33% 46 33% 60 33% 85

34% 25 34% 30 34% 37 34% 47 34% 61 34% 87

35% 25 35% 31 35% 38 35% 48 35% 62 35% 88

36% 25 36% 31 36% 38 36% 48 36% 63 36% 89

37% 26 37% 31 37% 39 37% 49 37% 64 37% 90

38% 26 38% 32 38% 39 38% 49 38% 64 38% 91

39% 26 39% 32 39% 39 39% 50 39% 65 39% 92

40% 26 40% 32 40% 40 40% 50 40% 65 40% 93

41% 27 41% 32 41% 40 41% 51 41% 66 41% 93

42% 27 42% 33 42% 40 42% 51 42% 66 42% 94

43% 27 43% 33 43% 41 43% 51 43% 67 43% 95

44% 27 44% 33 44% 41 44% 52 44% 67 44% 95

45% 27 45% 33 45% 41 45% 52 45% 67 45% 96

46% 27 46% 33 46% 41 46% 52 46% 68 46% 96

47% 27 47% 33 47% 41 47% 52 47% 68 47% 96

48% 27 48% 34 48% 41 48% 52 48% 68 48% 96

49% 28 49% 34 49% 41 49% 52 49% 68 49% 97

50% 28 50% 34 50% 41 50% 52 50% 68 50% 97

N = number.

Notes: These sample sizes are based on the Normal Approximation to the Binomial Distribution; a minimum sample size of 30 is required for 

this approximation to be valid. Shaded areas represent sample sizes of less than 30.

Appendix D-3. Determining Sample Size With a Margin of Error at ± 10 Percent
Volume II: Supplementary Methods, Statistics, and Data Collection 59

Appendix E. Example of a Form Used To Document 

Past Soil Disturbance in an Activity Area

Documentation of Soil Disturbance

Date: __________________________________________________________________

Project Name: __________________________________________________________

Stand or Unit ID: _______________________________________________________

Observer(s):____________________________________________________________

Name of Old Timber Sale (if known):_______________________________________

Lat./Long. and Datum:___________________________________________________

q No past disturbance visible

Check all that apply

Type Past Disturbance Approximate

Age/Timber Sale Name

Stumps*

– with disturbance nearby

– without obvious disturbance

Skid Trails

Excavated Skid Trails

Old Roads

– decommissioned

– storage

Skyline Corridors

Landings

Slash Piles

Horse Logging

Homestead/Pasture

Other

Comments:

*Stumps could be from ground-based, skyline, helicopter logging, or firewood cutting.
60 Forest Soil Disturbance Monitoring Protocol

Appendix F. Technical Specifications of Portable 

Data Recorders

Portable data recorders (PDRs) come in many varieties. It is possible, and not uncommon, 

to see scientists in the field carrying laptop computers, some with attached instruments 

that transmit data directly into a spreadsheet or database form. Many smaller devices 

provide almost the same capabilities, with the exception that data transfer occurs only 

when the device is connected to a computer after the user returns to the office. The type 

of PDR a user carries into the field depends partly on personal preference, partly on the 

capability of the device, and partly on what is available for purchase. Forest Service users 

generally are limited to what is listed on the corporate contract. Contracts change as new 

technology becomes available, so rushing to purchase one type of PDR may preclude 

acquiring another type better suited to the task.

In general, if the user is going to be constantly in motion or changing locations at regular 

or relatively short intervals, the device should be comparatively small, lightweight, and 

conveniently accessible. The device must be capable of running whatever software is 

used for the data recording and processing needs and must have sufficient storage capacity. An optional capability is wireless connectivity for immediate data transfer.

For the Forest Soil Disturbance Monitoring Protocol and use of the electronic field form, 

the requirements are as follows:

• Microsoft operating system (Pocket PC, Windows CE, etc.) or other operating 

system that can run compatible spreadsheet software.

• Pocket Excel (or Excel Mobile) or other compatible spreadsheet software.

• Screen that is visible in direct sunlight and under a thick forest canopy.

• Touchscreen or keypad data input.

• Connectivity for data download and upload.

The following specifications are highly recommended:

• Small (handheld or tablet).

• Lightweight, to allow for several hours of carriage at a time.

• Rugged and weatherproof, or with a padded and weatherproof case.

• Battery life of at least 8 hours.

• Serial and/or USB connectors.

• Minimum of 32MB of memory.
Volume II: Supplementary Methods, Statistics, and Data Collection 61

The following accessories are recommended:

• Additional storage capacity (e.g., compact flash cards).

• Rechargeable or spare batteries.

• In-car charger.

The following features are optional: 

• Network or wireless connectivity.

• Global Positioning System (GPS) card.

• Geographic Information System (GIS) display software.

• Carrying case.

• Bring laptop along (keep in car or at lodging) for nightly data transfer to ensure 

against data loss.

• If your PDR is not rugged or weatherproof, bring zipping-style bags and a lanyard 

to tie the recorder to yourself.

One choice is the Trimble or TDS Recon Pocket PC handheld field data collector ($1,799 

and up). Immersible and shock resistant, it runs Microsoft Windows Mobile 2003 software, which includes Pocket Excel and Pocket Word. It has an illuminated color touchscreen display (2 1⁄4” x 3 7/8”) with software, keyboard, and 64MB of active memory. 

The Recon Pocket PC can, in most cases, store an entire day’s data collection. The Recon 

also provides 64MB of flash memory for backups. If more storage is needed, two covered 

CF adapters are available for expanded memory. These can also accommodate add-ons 

such as GPS or a modem. The Recon Pocket PC runs GIS software called “SOLO” or 

“ARCPAD” that can help locate you in the field, including using background images, 

shapefile-format activity area polygons, and GPS location. 

The Recon uses a “PowerBoot Module” instead of standard rechargeable batteries. The 

PowerBoot Module, when fully charged, typically provides approximately 15 hours of 

battery life. An AC adapter/charger is included in the base price.

If you choose this option, we recommend the 400Mhz version, with 64MB of RAM and 

128MB of flash memory, to eliminate the need for additional cards. We also bought the 

optional in-car charger and extra data transfer cables. (We lost one almost immediately.) 

Our crews were able to remain in the field for extended periods, unconcerned about power 

loss or data storage limitations. 

Another, less expensive, choice is a Compaq (now HP) Ipaq 3600, which also runs 

the Pocket PC software. It has 32MB of memory, which is divided between “storage” 
62 Forest Soil Disturbance Monitoring Protocol

memory and “program” memory. Capacity can be expanded if you also purchase a hard 

sleeve, which incorporates a compact flash card slot. This product, however, is neither 

weatherproof nor shock resistant. Prices start at $499.99. Accessories such as in-car 

adapters are available. 

Drawbacks of these handheld recorders include a small viewing area—an important limitation due to the size of the input form used with the visual indicators. Also, input speed 

(response time of the mobile software to stylus taps) and the dexterity required for precise 

stylus tapping are factors that affect the efficiency of the exercise. A ruggedized upgrade 

of the Husky FeX21 is available; it runs Microsoft’s Handheld PC 2000 operating system, 

has a builtin keyboard, and is priced at $1,999.

Tablet-style recorders, with the ability to display an 8.5” x 11” page, are perhaps a 

better choice, providing a view of more of the data input spreadsheet. Prices range from 

~$850.00 to more than $2,000.00, depending on brand name and configuration. If you 

are able to purchase this option (there are two on the Forest Service contract as of May 

2009), remember that the response time is dependent on processor speed and RAM. Look 

for outdoor visibility, battery life, and ruggedness.

Other handheld computers may be comparable. Any unit that meets the requirements 

listed previously can be used. There may be compatible equipment that has fallen out of 

use in your local organization and can be borrowed or bartered. Husky Brand field data 

recorders were in vogue not long ago for use in cruising timber, etc. They are suited for 

the work presented in this guide, because they satisfy the operating system and software 

requirements, although they must be protected from the weather and handled with care. 

Check with local timber management personnel and others for availability.

A nontechnical alternative is to use paper forms in the field and transfer the data to the 

electronic spreadsheet upon return to the office or temporary duty station. One advantage 

to this method is that the drop-down lists useful on the PC version of the spreadsheet do 

not function after transfer to handheld, field-going PDRs—a consequence of the limited 

instruction set available in the mobile operating system. The lack of some sort of computer in the field, however, will require the user to rely on tables or hand calculations of 

the minimum required sample size and the statistical results of the monitoring activity.
Volume II: Supplementary Methods, Statistics, and Data Collection 63

Appendix G. Core Site Descriptors for Each 

Activity Area

This information is placed on form 1 of the FSDMPSoLo spreadsheet.

A separate report must be filed for each unit (or subunit) in a project. Definitions are 

provided in appendix D. To the extent possible, each report must include the following 

information: 

• Project ID: Usually a name, such as “Quarling Eagles” or “Marty Sale.”

Unit ID: Most often a number; could be alphanumeric, such as “12A.”

Project Type: For example, “Green sale,” “Salvage sale,” “Fuels Abatement.”

• Location

Region: Name, rather than number, to avoid cumbersome lookup.

Forest: Name, rather than number, to avoid cumbersome lookup.

District: Name, rather than number, to avoid cumbersome lookup.

• Map Information

USGS Quad(s): Name(s) of 7.5-minute quadrangle map(s) of site.

Geographic Coordinates: Either latitude & longitude (preferred) or UTM.

• Topography

Landform Description/Category: Such as “Glaciated hillslope” or “Alluvial terrace.”

Slope: In percent, the average or range of steepness of the unit or subunit.

Aspect: In degrees, the prevalent or range of direction the unit faces.

Elevation: In feet, the average or range of elevation of the unit or subunit.

• Ecology

Ecological Subsection: The alphanumeric subsection ID where the unit appears.

Habitat Type: The vegetative community classification of the unit.

Watershed ID: The name and the 6th-level HUC of the watershed containing the unit.

Watershed Condition Class: I, II, or III (defined in FSM 2521.1).

• Landtype Association: The mapping unit ID, based on landtype grouping.

Parent Material: Source material of the predominant soil on the site.

Soil Classification: The taxonomic descriptor of the predominant soil.

Soil Survey: Name of the published/accepted survey of the site area.
64 Forest Soil Disturbance Monitoring Protocol

• Site History

Fire Activity: Season and year of historic fire(s).

Harvest Activity: Season and year of previous harvest(s).

Grazing Activity: Span of years of allotted grazing.

Site Prep: Season and year and type of site prep work.

Planting: Year of planting, species planted, stocking rate.

Thinning: Year of thinning, residual stocking rate, species mix.

Reclamation: Of roads, landings, or other disturbance, the year(s).

Recreational Use: Type and duration of recreation activities.

• Current Activity

Prescription: Based on residual stocking rate, or “clearcut,” “dispersed shelterwood,” etc.

Logging System: Type of equipment used in current activity.

Monitoring Type: Number of months preactivity or postactivity.

Soil Moisture: Measured at time of monitoring.

• Summary Statistics: These will be filled automatically as transect is assessed.

• Administrative Information: Most of this information is filled automatically.

Observer Name:

Observer Title:

Date Monitored:

Date of Report:

Date Approved: {All reports must be approved by next-level line officer before final 

submission.}

Approver Name:

Approver Title:

NEPA Document: Title of NEPA document associated with this project.

Date NEPA Completed: